Three angles of a quadrilateral are equal and the measure of the fourth angle is 120°. Find the measure of each of the equal angles.

Question

Three angles of a quadrilateral are equal and the measure of the fourth angle is 120&#xB0;. Find the measure of each of the equal angles.

Philoid · Accepted Answer

Let x be the common angle of quadrilateral.

As per question,

A =B = C = x

D = 120°

As we know that, Sum of all four angles of quadrilateral is 360^o.

A + B + C + D = 360°

x + x + x + 120° = 360°

3x = 360° - 120°

3x = 240°

X = 240 / 3

= 80°

A =B = C = 80°

So, Three Angles of quadrilateral whose measuring’s are equal is 80°.