Prove two triangles are congruent by showing they satisfy one of four criteria. Find missing lengths by using the scale factor. The relationship between similar shapes may be expressed as a ratio.

1. Complete the following statements: (a) Two line segments are congruent if _____. (b) Among two congruent angles, one has a measure of 70°; the measure of the other angle is _____. (c) When we write ...

CBSE: Extra questions on Chapter 9 - Areas of Parallelograms and Triangles (for CBSE Class 9 Maths exam 2020-21) are available here. These NCERT based extra questions are important for the preparation ...

vi) (Motivate) If a side of a triangle is produced, the exterior angle so formed is equal to the sum of the two remote interior angles. 2. Triangles i) (Motivate) Two triangles are congruent if any ...