Question

The base angle of an isosceles triangle is 15° more than its vertical angle. Find its each angle.

Answer 1

Let the vertical angle of the isosceles triangle = x°

∴ Each base angle = x + 15°

∴ x + 15° + x + 15° + x° = 180°  ...(Sum of angles of a triangle)

⇒ 3x + 30°= 180°

⇒ 3x = 180° − 30° = 150°

∴ x =`(150°)/3=50°`

Hence vertical angle = 50°
and each base angle = 50° + 15° = 65°