You are here
Angles of Isosceles Triangles
Last updated at January 19, 2026 by Teachoo
Angles of Isosceles and Equilateral Triangles
Class 7 (Ganita Prakash 1, 2 & old NCERT)
Chapter 1 Class 7 - Geometric Twins (Ganita Prakash II)
- Introduction
- Figure it out - Page 3, 4
- Congruence of Triangles
- Figure it out - Page 8, 9
- Congruency involving Angles
- Figure it out - Page 14
- Other Congruencies
-
Angles of Isosceles and Equilateral Triangles
- Congruent Triangles in Real Life
- Figure it out - Page 20, 21
Transcript
Angles of Isosceles Triangles∆ABC is isosceles with AB = AC, and ∠A = 80°. What can we say about ∠B and ∠C ? Let’s first draw the figure To solve this, we construct altitude from vertex A to BC Now, by Corresponding parts of Congruent Triangles (CPCT) ∠ ABD = ∠ ACD Thus, we can write ∠ B = ∠ C This is a Property of Isosceles Triangle In an Isosceles Triangle, Angle opposite to equal sides are equal
