Question

In an isosceles triangle, the vertex angle is twice the each base angle. Find the vertex angle.

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Answer 1

let the base angle be X

Vertical angle = 2x

x+x+2x = 180

4x = 180

x = 180/4 = 45

2 × 45 ( vertex angle is twice the each base angle )

= 90.

Hence, the vertex angle is 90.