If a transversal intersect two parallel lines, then each pair of interior angles on the Same side of the transversal are Supplementary. Given: Two parallel Lines AB and CD, and PS be transversal intersecting AB at Q and CD at R. To Prove: Sum of interior angles on the Same side of the transversal is Supplementary. […]
Read More →Parallel Intersecting and Perpendicular Lines Definition: Parallel Lines Two or more lines in a plane that never intersect or touch each other are called “Parallel lines”. The symbol “∥” is used to denote parallel lines. Example- PQ ∥ RS denoted that line PQ parallel to line RS. Intersecting lines […]
Read More →Radius of a Circle The radius name comes from the Latin and its meaning is ray. Definition: Radius The distance from center of a circle to any point on the circle, or a line from center to any point on the circumference of a circle is known as “Radius”, of a circle. The […]
Read More →If a transversal intersects two lines, such that a pair of alternate interior angles are equal then the two lines are parallel. Given: Two lines AB and CD, and PS be transversal intersecting, AB at Q and CD at R. Each pair of alternate interior angles are equal. i.e. ∠BQR = ∠CRQ and ∠AQR = ∠QRD To Prove: AB ∥ CD Proof: Transversal […]
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 →If the angles subtended by chords of a circle at the center are equal, then the chords are equal. Given: A circle with center O, AB and CD are chords of circle that subtend equal angles at center O. i,e. ∠AOB = ∠COD. To prove: chord AB = chord CD Proof: In △AOB and △ CODOA = OC (Radius of circle)∠AOB […]
Read More →Equal chords of a circle subtend equal angles at the center. Given: Two equal chords AB and CD of a circle with center O. i,e. AB = CD. To prove: ∠AOB = ∠COD Proof: In △AOB and △ COD OA = OC (Radius of circle)OB = OD (Radius of circle)AB = CD (Given) Hence, △AOB ≅ △ COD (SSS Congruence rule) ∴ ∠AOB […]
Read More →Parallelograms on the same base and between the same parallels are equal in area. Given: Two parallelograms ABCD and EFCD, are on the same base DC and between the same parallel lines AF and DC. To prove: area (∥gm ABCD) = area (∥gm EFCD) Proof: In △ AED and △ BFC BC ∥ AD and AF is a transversal.So, ∠DAE = ∠CBF …..(1) (Corresponding angles of […]
Read More →Congruent triangles Worksheet Problems and Solutions Example : (1) In figure if AD = CD and AB = CB. (i) Find the three pairs of equal parts in △ABD and △CBD. (ii) Is △ABD ≅ CBD ? Why or why not? (iii) Does BD bisect ∠ABC? give reason. Solution : (i) In △ABD and △CBD, three pairs of equal parts […]
Read More →A diagonal of a parallelogram, divides it into two congruent triangles. Given: A parallelogram ABCD and AC is a diagonal, the diagonal AC divides parallelogram ABCD into two triangles △ ABC and △ CDA. To prove: These triangles △ ABD and △CDA are congruent, △ ABC ≅ △ CDA Proof: In △ ABC and △ CDA BC ∥ AD and AC […]
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