Question

The 3 angles of a quadrilateral are equal and the measure of the fourth angle is

1200

. Find the measure of the 3 equal angles​

Answer 1

Let x be one the three equal angles.

Sum of all the angles of a quadrilateral = 360°

⇒ x + x + x + 120° = 360°

⇒ 3x = 360° -120°

⇒ 3x = 240°

⇒ x = 80°

Thus, the measure of each of the equal angle is 80°.