Question

One angle of a triangle is 80° and the other two are in the ratio 3 : 2. Find the unknown angles of the triangle

Answer 1

Let angle ∠A of a triangle ABC = 80°

But sum of three angles of a triangle = 180°

Sum of remaining two angles = 180° – 80° = 100°

Ratio in their two angles = 3:2

Let second angle = 3x

and third angle = 2x

3x + 2x = 100°

5x = 100 x = `100/5` = 20°

second angle ∠B = 3x = 3 x 20° = 60°

and third angle ∠C = 2x = 2 x 20° = 40°

Hence other two angles are 60° and 40°.