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 →

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 →

Angles opposite to equal sides of an isosceles triangle are equal. Given: A isosceles triangle △ ABC in which AB = AC, andangles opposite to equal sides of triangle are ∠B and ∠C. To prove: We need to prove that ∠B and ∠C, are equal                           ∠B = ∠C. Construction: Draw the bisector […]

Read More →

The side opposite to equal angles of a triangle are equal. Given: A triangle △ ABC in which angles opposite to sides AC and AB of are ∠B and ∠C, and  ∠B = ∠C. To prove: We need to prove that sides AB and AC, are equal                           AB = AC. Construction: Draw […]

Read More →

Supplementary and Complementary Angels To understand supplementary and complementary angles, first we need to understand the adjacent angles.                          Adjacent angle Two angles that have a common vertex and a common side but not overlap, are known as adjacent angles.    Complementary Angles When the total of […]

Read More →

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”, and vertical angles are always “Congruent” They are also called  “Vertically Opposite Angles”.                      In above […]

Read More →