Diagonals of Polygon’s In geometry, a line segment joining two vertices of a polygon or polyhedron, when those vertices are not adjacent is known as Diagonal.  Diagonals of Polygon’s A polygon’s diagonal’s are line segments, that joining from one corner to another corner. Formula for number of diagonals = n(n-3)/2 where n is number of sides or […]

Read More →

Polygon – Interior and Exterior & Central Angles Interior angle of a regular 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. When a polygon has n sides n vertices and n interior angles. Interior angle = 1800 – Central angle […]

Read More →

 Theorem : In a parallelogram, opposite angles are equal.  Given: A parallelogram ABCD,  opposite sides of parallelogram are                         side AB and side DC                         side AD and side BC. To prove: Opposite angles of parallelogram are equal. […]

Read More →

History of Coordinate Geometry The Cartesian system or the rectangular coordinate system was invented in seventeenth century by Rene Descartes, the great French philosopher and mathematician. The coordinate system is also called the Cartesian system. Geometry was well developed to describe the dimension of an object, but it does not describe the position of an object. So, to […]

Read More →

SSS, SAS, ASA, AAS and RHS – Congruence of Triangles  In geometry we see that, if two line segments are are same in length, they are congruent, and if two angles are same in measure they are also congruent,.Simply, we can say congruent means an object and its mirror image. Congruence Triangles A triangle is a polygon with […]

Read More →

Area of a Triangle In this lesson we will learn, how to calculate the area of a triangles with different formula’s. When given 1. The base and height of a triangle.2. Two sides and one angle.3. The length of three sides.4. An equilateral triangle. First we see about a triangle.  A triangle is a simple […]

Read More →

           Similar Figures – Definition and Examples Definition:  If two figures have the same shape, then they are called ” Similar Figures”. The ratio of length of their corresponding sides are equal, and their corresponding angles are equal. In below triangles ABC and PQR corresponding angles are equal so,      […]

Read More →

 Elements of a Parallelogram In figure a Parallelogram ABCD.  There are four sides AB, BC, CD and DA and four angles ∠A, ∠B, ∠C and ∠D in a Parallelogram. AB and DC are opposite sides, and AD and BC are another pair of opposite sides. ∠A and ∠C are a pair of opposite angles, and another pair of opposite angles are ∠B and ∠D. AB […]

Read More →

Definition, Properties, Examples – Cyclic Quadrilaterals What is a Cyclic Quadrilateral A cyclic quadrilateral is a four sided polygon that is inscribed in a circle. The vertices are said concyclic. The center of the circle is called circumcenter and radius of the circle is called circumradius. Definition: A Cyclic Quadrilateral is a quadrilateral, whose all four vertices […]

Read More →

        The Pythagoras Theorem A long time over 2000 years ago, a Greek mathematician named Pythagoras discovered an amazing and interesting property about Right triangles, The square of the length of the hypotenuse equals the sum of the squares of the lengths of the other two sides.  This property now called Pythagoras […]

Read More →