Question

The ratio between the base angle and the vertical angle is 2:5 find each angle of the triangle

Answer 1

Given ratio between the base angle and vertical angle of an isosceles traingle is 2:5

⇒ base angle / vertical angle = 2 / 5

let base angle = x

⇒ verticle angle = (5/2)x

we know that
verticle angle + base angle + base angle = 180°

⇒ ( 5/2 + 1 + 1 ) x = 180°

⇒ (9/2)x = 180°

⇒ x = ( 180° x 2) / 9

⇒ x = 40°

verticle angle = (5/2) x 40° = 100°
base angle =40 degree
vertical angle=100 degree
there for angle of triangle become 40degree,40 degree,100 degree
which is an isosceles traingle.