# Mathematics Dictionary – Mathematical – Terms – Definitions

## Mathwords A to Z With Meanings

There are many types of dictionaries. English-Dictionary Graph-Dictionary etc, Graph-Dictionary contains all types of graphs English-Dictionary is common dictionary.

In math-Dictionary we can find list of more than 2100 mathematical words and their meanings.

Dictionary is a book in which we can see the meaning of each and every word.

In math dictionary given the meaning of all mathematical words.

This is helpful for students, if students doesn’t understand a particular word he/she can take the help of the dictionary.

Math dictionary is also helpful for parents and teachers.

**Abacus**

An Abacus is an instrument, which is a collection of beads that slide on rods.

**Abscissa**

Abscissa is the value of the X coordinate on a coordinate plane.

In a coordinate plane the abscissa is the X coordinate of a point.

The Horizontal line is called the X axis, and abscissa is the value of the X axis on a coordinate plane.

The distance of a point from the Y axis is called its X coordinate or Abscissa.

The abscissa always comes first in an ordered pair.

**Accuracy of measuring**

Accuracy of measuring means all measurements are approximates. Accuracy of measurement depends on the quality of instrument and person used to measuring.

**Acute angle**

A angle whose measure is more than 0 degree and less than 90 degree is called a acute angle.

**Adjacent sides**

Two sides of any polygon that have a common vertex.

**Acute triangle**

If in a triangle, all three angles are less than 90 degree, the triangle called acute triangle.

or^{ }

An acute triangle has three acute angles, or in an acute triangle, all angles are less than 90 degree, so all angles are acute angles.

**Addition **

Total is amount of two or more numbers or things.

When we add 5 and 2 we get 7

5 + 2 = 7

Add, addition, plus and sum are related terms.

This is the opposite of subtract.

**Addition of One**

When we add one to any number the total will be next number of the number.

**Addition of polynomials**

Addition of polynomials means we simply add the like terms.

**Additive inverse**

In mathematics, the additive inverse of a number is what we add to a number to create the sum of zero.

**Adjacent angles**

If two angles have a common vertex, and a common arm but the non common arms are on either side of the common arms, so the Adjacent angles are a pair of angles.

**Algebra**

The most general form of algebra is the study of mathematical object in abstract algebra is called an algebra.

In algebra uses letters like x,y a and b or other symbols in place of values, and the rules for manipulating these symbols.

A branch of mathematics that substitutes symbols or letters for unknown numbers.

Example: A simple algebraic equation

3x + 4 = 16

3x = 16 – 4

3x = 12

x = 12/3

x = 4

**Algebraic Expression**

An Algebraic Expressions is combination of constants and variables along with operations addition, subtraction, multiplication and division (+, -, x, ÷).

**Arc**

An arc is a portion of the circumference of a circle. It is also known as circular arc.

**Arc length**

An arc is a smooth curve and the length of a arc is known as arc length.

**Area**

Area is the measure of how much space of a two dimensional surface.

**Area of a circle**

Area of a circle is A = 𝝿r^{2}

^{= }𝝿 (pi)^{ }x (radius)^{2} , where r is radius of the circle.

**Area of triangle **

Area of triangle is equal to half of the product of its base and height.

If given the length of three sides of a triangle, then we can use the formula to find the area of triangle.

**Arithmetic**

Arithmetic is a branch of mathematics in which we studied the numbers and relations among numbers.

The basic arithmetic operations are addition, subtraction, multiplication and division.

**Ascending order**

When we arrange the data from smallest to greatest,

order it is called Ascending order.

**Algorithm**

A method for solving problems in mathematics with step by step.

**Alternate angles**

When two lines are cut by a third line (transversal) alternate angles are between the pair of lines on the outside of the transversal.

If the two lines are parallel, the alternate angles are equal.

**Angle**

In plane geometry, angles are formed by two rays or lines called the sides of the angle, sharing a common endpoint, called the vertex of the angle.

**Apex**

Apex The highest point or vertex in a plane shape, geometric or polyhedron.

**Arms of an angle **

When two rays meet a common end point they formed an angle. The common point is called the vertex and rays are called the arms of the angle.

**Array **

Array is a rectangular diagram, divided into rows and columns, rows are horizontal and columns are vertical.

**Attribute **

The attribute of a 2D shape is its size or shape.A 2D shape have more than one attribute.

**Axis of Symmetry**

A line is drawn from the middle of the figure that acts like a mirror is known as Axis of Symmetry or Linear Symmetry.

**Base**

The bottom line of a surface.

**Bisect **

Bisect means divide into two equal parts. We can bisect angles lines and more.

**Binomial**

An expression in algebra that consists of two terms.

**Brackets**

Brackets are symbols used in mathematical notation such as parentheses or round Brackets (), square Brackets or box Brackets [], Braces or curly Brackets {}.

**Bar graph **

A graphical representation of data, in which bars show comparisons between categories of data.

A bar graph is a simplest representation of data.

**Binomial**

An algebraic expression have two terms is called binomial.

**‘BODMAS’ Rule**

The ‘BODMAS’ is an acronym which stands for, order of mathematical operations, as Bracket, Order,

Division, Multiplication, Addition, and Subtraction.

**Corresponding angles **

When two lines are cut by a third line or transversal they form corresponding angles.

Corresponding angles have in corresponding positions i.e. on the same side of the transversal, both angles are above or both angles are below of the pair of the lines.

If the lines are parallel, the corresponding angles are equal.

**Calendar**

A calendar is a system of organising time into days, weeks and years.

**Calculus **

The word Calculus comes from Latin and it’s meaning is “small stone”. Calculus is a branch of mathematics, originally called infinitesimal calculus or the calculus of infinitesimals. Calculus involving the mathematical study of derivatives and integrals.

**Capacity **

The amount that a container can hold.

**Categorical data **

When an information can be put into different non-numerical groups. Census A survey of the entire population.

**Clock**

Clock is an instrument used to display the time.

There are many different types of clocks, but the most common are analog with hands for hours, minutes and seconds and other is digital, which displays only digits.

**Census **

A survey of the entire population.

Clock Clock is an instrument used to display the time.

**Co- interior**

When two lines are cut by a third line or a transversal, form angles. Angles are form between the pair of lines on the same side of the transversal are known as co-interior angles.

If the lines are parallel the co- interior angles are supplementary(180 degree).

**Column**

A vertical arrangement of items.

**Column graph**

A Column graph is a graph in which the information is show in columns for easy compression. It is also known as a Bar chart.

**Compass directions**

The directions shown by a compass is Compass directions.

Example- North (N), South (S), East (E), West (W), North East (NE), South West (SW) and North Wast (NW).

**Complementary angles**

When two angles are added together the measurement of angles is equal to 90 degrees such as angles are called Complementary angles, and each angle is a complement of other angle.

**Concave quadrilateral**

A concave quadrilateral have a reflex angle and one or more of its diagonals lies outside of the figure.

**Cone **

A cone is a three dimensional (3D) object with an apex and a circular base.

**Congruent **

The same shape and same size.

**Continuous data**

Continuous data are numerical (quantitative) data that is obtained by measuring.

For example- Height, Weight, length, temperature.

Conversion graphs

Conversion graphs are used to convert from one unit to another unit.

**Convex quadrilateral**

Convex quadrilateral have diagonals inside of the figure.

**Coordinates**

Coordinates shows the position of a point or space on a map or grid by a set of numbers or letters.

**Cross-section**

When a solid is cut through parallel to the base the shape we get a cross-section.

**Cylinder**

A cylinder is a three- dimensional (3D) object with two circular bases that are the same size and same shape and opposite to each other in position.

**Cardinality of a infinite set**

The cardinality of a set X is n(X) = a, where a represents the number of elements of set X.

**Cardinal Numbers**

1, 2, 3, 4, 5,…..etc are called Cardinal Numbers.

1st, 2nd, 3rd, 4th, 5th…are called Ordinal Numbers.

**Cartesian Coordinate plane**

A Cartesian Coordinate plane is defined by two intersecting number lines at a 90 degree angle (perpendicular number lines), and the point where they intersect is known as origin.

**Centre of a Circle**

The point equidistant from the points on the circle is known as Centre.

**Central angle of a circle **

The angle between two radii of a circle is known as the Central angle of the circle.

**Central angle of a regular polygon**

A angle whose vertex is centre of the regular polygon and sides are radii to the end points of the same side of the polygon, is known as the central angle of the regular polygon.

** Chart **

A chart is a graphical representation of data, in a chart the data is represented by symbols, such as a bar chart represented by bars, pie chart by slices or a line chart by lines.

**Chord**

A line segment joining two end points, that lie on a circle is Chord.

**Circle**

A circle is a collection of all the points in a plane, whose all points are same distance from a fix point, is called circle.

**Circumference**

The length of the complete circle is called circumference. It is half of diameter.

**Complete angle**

A right angle whose measure 360 degree is called a complete angle.

**Composite** numbers

Composite numbers are whole numbers that have more than two factors.

**Concave** polygon

If a polygon has one are more interior angles is greater than 180^{0 }then it is called a concave polygon.

**Commutative Property of Addition**

Whenwe are doing addition, the numbers can be added in any order, and we will get same result.

**Commutative property of Multiplication**

Whenwe are doing multiplication, the numbers can be multiplied in any order, and we will get same result.

**Complete angle**

A right angle whose measure 360 degree is called a complete angle.

**Complement of A**

Let U be the Universal set and A is subset of U, then the Complement of A is set of all elements of U which are not the elements of A.

**Congruence figures**

Two figures or objects are called congruent when one object cover the other completely and exactly.

**Convex polygon**

If all the interior angles of a polygon is must be less than 180^{0 }then it is called a convex polygon.

**Co – Prime Numbers **

Two numbers which do not have any common factor other than 1, and HCF of these numbers is 1.

are called Co – Prime Numbers.

**Cost price**

The cost price is the price at which a product or

service is purchased by seller.

**Cube**

A cube is a solid box of six square faces, all of which sides have equal in length and every square is same in area.

**Cuboid**

A cuboid is a closed three dimensional figure with length, breadth and height.

**Cube root**

The Cube root of a number is a number when multiply three times gives that number.

**Cyclic Quadrilateral**

A Cyclic quadrilateral is a quadrilateral whose all four vertices’s passed through the circle or touch the circumference of circle is called the Cyclicquadrilateral.

**Decagon**

Decagon is a polygon with ten straight sides and ten interior angles.

In a decagon if all sides and angles are equal it is called a regular decagon, and if all sides and angles are not equal it is an irregular decagon.

**Descending order**

When we arrange the data from greatest to smallest, order it is called Descending order.

Example- counting numbers 10, 9, 8, 7, 6, 5, 4, 3, 2… are in descending order.

**Decimal**

A number whose whole number part and fractional part is separated by a decimal point is known as a decimal number.

A dot (.) represents a decimal point.

When the numbers are expressed in the decimal form are called decimal numbers.

A fraction that is made by dividing a whole into tenths

Degree (angles) Plural of degree is degrees.

**Degree (Celsius)**

A unit of measurement used for temperature. The symbol is 0^{0. }^{ }

Denominator is the bottom part of a fraction.

Example- In fraction 4/5, 5 is denominator.

**Depreciation**

Depreciation, when an item loses value over time.

**Difference**

Result of subtraction.

The difference of 25 and 15 is 10 (25 – 15 = 10)

**Differential Calculus**

The basic idea of differential calculus is the study of instantaneous rates of change and slope of curves.

**Digit **

In our number system a symbol used to write a numeral. The digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, all are used to write numbers in our number system.

Example- 18 is a two digit number.

245 is a three digit number.

4569 is a four digit number.

**Digital clock**

Digital clock display the time in digits.

**Division**

Division is breaking a number into equal number of groups or parts.

Division is represented by symbol** ÷**

**Dodecahedron **

A three – dimensional (3D) object with 12 faces.

**Divisibility**

Divisibility test is a quick test to see that a number can be divided by another number without remainder.

Example: If a number ending in 0 is always divisible by 10.

If a number ending in 5 or 0 is always divisible by 5.

**Difference of two sets**

The difference of two sets A and B, is set of elements which belong to a A but not B.

**Diagonal**

In geometry, a line segment joining two vertices of a polygon or polyhedron, when those vertices are not adjacent is known as Diagonal.

or

A polygon diagonal are line segments, that joining from any two vertices (corners), where the vertices are not next to each other.

**Diameter**

The longest distance that has the end points on the circle and passes through the centre is called Diameter.

**Disjoint sets**

Two are more sets are said to be Disjoint sets if they have no common elements.

**Dividend**

The number which we divide is called the dividend.

### Divisor

^{}^{}The number by which we divide is called the divisor.

**Double Bar Graph**

When we compare to data groups of information, situations or events we use Double Bar Graph.

**Element of a set**

A number, letter or any object contained in a set is known as Element of a set.

**Empty set**

A set which does not contain any element is called Empty set, or null set or void set.

**Equal Sets**

The two given sets have member of elements and the number of elements are exactly same, then the sets are called Equal Sets.

**Equivalent sets**

Two sets are Equivalent sets, if they have different elements but have the same number of elements.

**Euler’s formula **

A relationship between the number of vertices (V), edges (E) and faces (F) of a polyhedral. The relationship is V + F – E = 2.

**Edge **

The line where two flat surfaces meet.

**Equal sign**

The symbol equal sign (=) is used to indicate the equality of two or more amounts that have the same value.

The symbol of equal sign is denoted by (=)

Example- 4 + 5 = 10 – 1

**Equal groups**

Equal groups have the same number of objects or items.Objects putting together in equal groups helps us to understand multiplication and division.

Equals Share into equal groups or parts, or has the same value.

Example Divide 8 books between 2 children, each children get 4 books.

**Equivalent**

Has the Same value.

**Equation**

An equation is a mathematical expressions that using the equal sign (=) to show that one side has the same value as the other side.

Example- 7 x 3 = 21

**Equilateral triangle**

If in a triangle, all three angles are equal,and each angles are 60 degree, the triangle called equilateral triangle.

**Equivalent Fractions**

Fractions which represent same or equal value, known as Equivalent Fraction.

**Even number**

If we divide any integer by 2, and remainder is zero, we get an Even number.

**Exponent**

When a number repeatedly multiply by itself, we raise it to a power. This is known as Exponent.

**Exterior of the circle**

Outside the circle, which is called the Exterior of the circle.

**Face**

In a 3D (three dimensional) object, one of the flat surfaces.

**Factor**

A number break up into another numbers that can be multiplied together and get original number.

or

A number that divides into another number exactly and without leaving a remainder is a Factor.

or

A factor is a number that is divisible by another number and the quotient is an integer.

**Factor tree**

A factor tree is a tree diagram where we find the factors of any number, then factors of those numbers until we can’t factors any more.

**Fibonacci sequence**

Numbers following a sequence in which each subsequent number is the sum of the previous two numbers.

Example – This sequence starts with 1:

1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8, 5 + 8 = 13,…

The numbers 1, 1, 2, 3, 5, 8, 13…

**Finite Set**

If a set contains finite or limited or (countable) number of elements is called Finite Set.

**Flip**

A reflection – Turn over to give the mirror image.

**Fraction**

If we divide an object into equal number of parts, then each part is known as a Fraction.

**Fraction notation**

A number in the form a/b, where a and b are numbers and b is not equal to zero.

**Frequency Histogram**

A histogram is from of graphical representation of grouped frequency distribution with continuous classes.

**Frequency Polygon**

In a frequency polygon the number of observations is marked at the the midpoint of the interval with a single point, and a straight line connects each set of point.

**Globe**

Globe is a spherical model of earth. Globe is a

perfectly round 3D shape, with the help of a globe we can see the entire earth at a glance.

**Graph **

A Graph is a mathematical diagram which shows collection of information.

Example- Line graph, Bar graph, Pie graph etc.

**Grouped data**

Grouped data are data that has been organised in groups known as classes.

**Highest Common Factor**

The”Highest Common Factor” (HCF) of two or more numbers is the highest or greatest of their common factors.

**Hypotenuse**

In geometry, the longest side of a right-angled triangle, the side opposite the right angle is known as hypotenuse.

The square on the hypotenuse is equal to the sum of the squares on the other two sides.

**Improper Fraction**

A Improper Fraction is a fraction whose numerator is greater than it’s denominator.

**Infinite Set**

If a set contains unlimited or (uncountable) number of elements is called an Infinite Set.

**Interest**

Interest is the extra money that the borrower paid in addition to the principal.

**Integral calculus**

Integral calculus concerns accumulation of quantities and find areas under and between curves.

**Interior angle of a polygon**

A regular polygon has all the interior angles same in measure, and all interior angles of polygon formed by each pair of adjacent sides.

**Interior angle of a circle**

Inside the circle, which is called the Interior of the circle.

**Intersecting Lines**

Two or more lines in a plane that meet at a point are called Intersecting Lines.

**Intersection of two sets**

The Intersection of two sets A and B is the set of all elements, which belong to both A and B.

**Irrational Number**

An Irrational Number is a Real Number that cannot be expressed as a simple fraction for any Integers.

**Irregular polygon**

A polygon which has all sides are not congruent(not equal) or different in length and all angles are not congruent (not equal) or different in measure the polygon is known as a irregular polygon.

**Isosceles triangle**

If in a triangle, two angles are equal and two sides are equal, the triangle called isosceles triangle.

**Law of cosines**

If all three sides of a triangle (SSS) are given, the cosine rule allows one to easily find any of the angle measures.

Similarly, if two sides and the angle between them is known, the cosine laws can be used to calculate the third side of the triangle.

**Law of Sines **

In trigonometry, the law of Sines says that in any given triangle, the ratio of any side length to the sine of its opposite angle is the same for all three sides of the triangle.

**Law of tangents**

In trigonometry, the law of tangents describes the relationship between the sum and difference of sides of a right triangle and tangents of half of the sum and difference of the angles opposite to the sides.

**Like Fractions**

Fractions with same denominators (bottom numbers) are called Like Fractions.

**Like terms**

Like terms are terms that have same variables with same exponents.

**Line**

A line is straight (no curves), has no thickness, and extends indefinitely in both directions.

**Line graph**

A line graph is a type of a graph which show how data or information change over time.

**Linear equation in two variable**

If the equation has more than one variable and the highest power of variable, appearing in the equation is 1, such that variables are not multiplied each other then this type of equation is known as “linear equation in two variable”.

**Line segment**

A line segment is a part of a line, which has two endpoints, and contain all of the points between the two end points.

**Loss**

The difference between cost price (CP) and selling price (SP) is positive, that amount is called Loss.

**Mixed Fraction **

A “Mixed Fraction” is combination of a whole and a part.

**Mixed Number **

Mixed Number is combination of a whole number and a fraction.

**Monomial**

An algebraic expression have only one term is called monomial.

**Multinomial**

An algebraic expression have more than one term is called multinomial.

**Multiple **

In, math, multiple of a number, is a number that is the product result of one number multiplied by another number.

**Natural Numbers**

The counting numbers (1, 2, 3, 4, ……..) are known as Natural Numbers or counting numbers.

**Negative rational numbers**

While we write Negative rational numbers we put negative sign in front of the number or with the numerator.

**Obtuse angle**

A angle whose measure is more than 90 degree and less than 180 degree is called a obtuse angle.

**Obtuse triangle**

If in a triangle, one angle is more than 90 degree, the triangle called Obtuse triangle.

or

An obtuse triangle has an obtuse angle, an obtuse angle, has more than (90 degree).

### Odd number

If we divide any integer by 2, and remainder is one, we get an Odd number.

### Operation on set

An Operation on set, is where two are more sets combined, and form one set under the given conditions.

**Ordinal numbers**

Ordinal numbers indicated position or order in relation to other numbers.

**Ordinate**

Ordinate is the value of the Y coordinate on a coordinate plane.

**Overlapping Sets**

If two sets have atleast one common element are said to be Overlapping Sets.

**Place valu**e

The place value is position or value of a digit.

**Parallelogram**

A Parallelogram is a quadrilateral, whose both pairs of opposite sides are parallel and equal in length.

**Parallel Lines**

Two or more lines in a plane that never intersect or touch each other are called Parallel Lines

**Percent**

A Percent is a number or ratio expressed as a fraction of 100, in other words Percent is a fraction of denominator 100.

**Perimeter**

The distance that surrounds a two dimensional shape is known as Perimeter.

**Perimeter of a square**

Perimeter of a square is sum of the length of its sides.

**Perpendicular Lines**

A line intersect another line and the angle between

them is a right angle or 90^{0} then the lines are said to be Perpendicular.

**Pictograph**

A Pictograph represents statistical data through pictures of objects.

**Pie graph or Pie Chart**

A Pie graph or Pie chart is a circular chart divided into sectors, each sector represents a proportionate part of a whole.

### Point

When by a sharp tip of the pencil, mark a dot on the paper it will be the point.

### polygon

A polygon is a two-dimensional shape form with more than three straight lines.

### Polygon diagonal

A polygon diagonal are line segments, that joining from one corner to another corner.

### Polynomial

If in an algebraic expression the power of variables is a non negative integer, then the expression is called a polynomial.

**Positive Number**

A Positive Number is a number that is greater than zero.

**Power set**

The Collection of all Subsets of a Given Set, is known as Power Set.

**Predecessor**

For a given number Predecessor number is obtaining by subtraction 1 from it.

**Prime number**

A prime number is a natural number greater than 1, with exactly two factors. A prime number is only divisible by 1 and itself.

### Principal or Sum

The money borrowed or lent out for a certain period is known as the principal or the sum.

**Profit or Gain**

When the difference between selling price (SP) and cost price (CP) is positive, that amount is called profit or gain.

**P**roper Fraction

A “Proper Fraction” is a fraction whose numerator is smaller than it’s denominator.

Example: 1/2, 3/4, 5/6, 8/11, 9/15, etc. all are proper fractions, where numerator is smaller than denominator.

**P**roper Subset and Super Subset

A and B are two sets. If A⊂B and A ≠ B, then A is called a Proper Subset of B, and B is called Super Set of A.

**Proportion**

When two ratios or (fractions) are equal, then they

are in Proportion.

### Protractor

A Protractor is an instrument, that measures angles in degree.

### Quadratic Equation

If p(x) is a polynomial of degree 2, of any equation in the form p(x) = 0, is a Quadratic equation.

### Quadrilateral

A quadrilateral is a simple closed curve or a polygon with four edges or sides and four vertex or corners.

### Quotient

In division process the result we get is called the quotient.

### Radius

The distance from centre of a circle to any point on the circle, or a line from centre to any point on the circumference of a circle is known as Radius of a circle.

### Range

The distance between the highest and lowest value in a set is known as Range.

### Range of Data

^{}The difference between the highest and the lowest values of the given data is called the range of the data.

**Rational Number**

Numbers which can be written in the form p/q, where p is and q are integers and q≠0, p is numerator and q is non zero denominator called a

Rational Number.

**Ray**

A ray is a portion of a line. It starts at one point called starting point and extends infinity in one direction.

**Rectangle**

A Rectangle is a quadrilateral, whose every internal angle is right angle or 90 degree and both pairs of opposite sides are parallel and equal in length.

**Reflex angle**

A angle whose measure is more than 180 degree but less than 360 degree is called a reflex angle.

### Regular Polygon

A polygon which has all sides are congruent(equal) and all angles are congruent (equal) is known as a regular polygon.

### Remainder

In division process the number left over is called the reminder.

**Rhombus**

A rhombus is a quadrilateral (closed shape, plane figure) with four straight sides that are equal length also opposite sides are parallel and opposite angles are equal.

A rhombuses is a type of parallelogram.

**Right angle**

A right angle is an internal angle, whose measure is 90 degree.

**Right Circular Cylinder**

A Right Circular Cylinder is a three dimensional object, whose base is circle and the height (axis) is the line joining the centres of bases.^{}

### Right triangle

If, in a triangle one angle is 90 degree, the triangle called right triangle.^{ or }

A right triangle has a 90^{0 }angle.

**Right Isosceles triangle**

If in a triangle one right angle and two angles and two sides are equal, the triangle called isosceles triangle.

**Roman Numerals**

An ancient system of writing numbers used by Romans, is called Roman Numerals.

**Selling price**

The selling price is the price at which a product or service is sold to the buyer.^{}

**Scalene triangle**

If in a triangle, any angles and any sides are not equal, the triangle called scalene triangle. in other words, each side have different length each angle must have a different degree.

**Similar Figures**

If two figures have the same shape, then they are called ” Similar Figures”.

**Similar polygon**

Two polygons are similar if they have same shape, but not the same size.

**Singleton set**

If a set has only one element is known as Singleton set.

**Square**

A Square is a quadrilateral, whose every internal angle is right angle or 90 degree, four sides are equal in length and both pairs of opposite sides are parallel.

**Square root**

The Square root** ** is the inverse operation of squaring that number.

**Straight angle**

A angle is an whose measure 180 degree is called a straight angle.

### Subset

A set A is said to be a subset of a set B, if every element of A is also an element of B.

### Successor

When we add one to any number and get next number that is called the Successor.

**Tangent of a circle**

A straight line that intersects the circle, at only one point is a “Tangent”.

**Theorem**

In mathematics a theorem is a statement, that has been proved to be true on basis of facts that were already known and used in previously established statements.

**Transversal**

A Transversal is a line or line segment, that intersects two or more lines or line segments.

**Trapezium**

Trapezium is quadrilateral whose a pair (base) of sides are parallel.

**Triangle**

A Triangle is a simple closed curve or a three sided polygon.

### Trinomial

An algebraic expression have three terms is called trinomial.

### Ungrouped data

^{}The data is in an original form called raw data or Ungrouped data.

### Unlike Fractions

Fractions with different denominators (bottom numbers) are called Unlike Fractions.

**Unlike terms**

The terms that do not have same variables or power are called unlike terms.

**Union of two sets **

The Union of two sets A and B is the smallest set, which contains all the elements of both sets and

taking every element of both sets A and B, without repeating any element.

**Universal Set**

The set that contain all the elements of a given collection, and therefore all sets are subset of the Universal Set is called the Universal Set.

**Variable**

Variables are symbol or letters that used to represent for unknown numbers or values.

**Venn diagram**

The relationship between sets can be represented by diagrams is known as Venn Diagrams.

**Vertical angles**

When two lines are intersect they made four angles, angles are opposite to one another at the intersection of two lines.Each opposite pair of angles are called Vertical Angles.

**Volume**

^{}A shape’s volume is the measure of the amount of total 3- dimensional space inside it, like a ball, cube, cylinder or pyramid.^{}Volume is measured in cube.

**Vertex**

Vertex is a common endpoint of two or more rays or line segments.

**Whole numbers**

When we add the number zero (0) to the natural numbers, we get Whole numbers.

**X – Axis**

The Horizontal axis of a coordinate plane is called the X axis.

**X – coordinate**

The first number occurs in an ordered pair (a,b).

**Y – coordinate**

The second number occurs in an ordered pair (a,b).

**Y – Axis**

The Vertical axis of a coordinate plane is called the X axis.

**Zero pair**

Any natural number x, x + (- x) is called a zero pair because their sum is zero.