Question

If the vertex angle of an isosceles triangle is 50°, find the other angles.

Answer 1

Given: ∠A = 50° and AB = AC

To Find: ∠B and ∠C

Proof:

AB = AC (Given)

∠B = ∠C (Angles opposite to equal sides are equal)

In ΔABC, ∠A + ∠B + ∠C = 180° (Sum of the angles of a triangle)

50° + ∠C + ∠C = 180°

2 ∠C = 180° − 50°

2∠C = 130°

∴∠C = 65°

⇒∠B = 65°