Question

Find the measures of the angles of an isosceles triangle in which each of the base
angles is four times the vertical angle.

Answer 1

Answer:

Let vertical angle of an isosceles triangle = x

∴ Each base angle = 4x

∴ x + 4x + 4x = 180°

(Sum of angles of a triangle)

⇒ 9x = 180° ⇒ x = 180°/9 = 20°

∴ Vertical angle = 20°

and each of the base angle = 4x

= 4 x 20° = 80°