Question

The ratio between a base angle and the vertical angle of an isosceles triangle is 1: 4. Find each angle of the triangle.

Answer 1

Ratio between base angle and vertical angle of an isosceles triangle = 1: 4

Let each base angle = x
then vertical angle = 4x

∴ x + x + 4x = 180° .........(Sum of angles of a triangle)

⇒ 6x = 180°

⇒ x =`(180°)/6=30°`

∴ Each base angle = x = 30°and vertical angle = 4x
= 4 × 30° = 120°