Question

Two angles of a triangle are equal and its third angle is double of the equal angle. Find the
measure of the three angles of the triangle.​

Answer 1

Let the three angles be x, x and 2x

(Sum of all angles of a triangle = 180°)

Then, x + x + 2x = 180

4x = 180

x = $\frac{180}{4}$ = 45°

Therefore, the 1st angle = x = 45°

                  the 2nd angle= x 45°

                  the 3rd angle = 2x = 2 × 45 = 90°