Question

Three angles of a quadrilateral are equal and the fourth angle measures $120°$. What is the measure of each of the equal angles?

Answer 1

It is given that three angles are equal and the measure of the fourth angle is $120°$

Let the measure of each of the equal angles be $x°$

We know that sum of four-measure of angles of a quadrilateral is $360°$

$$\begin{gathered} x+x+x+120=360 \\ 3x+120=360 \\ 3x=360-120 \\ 3x=240 \\ x=\frac{240}{3} \\ x=80 \end{gathered}$$

Therefore, the measures of each of the equal angles $80°$