x=30
Explanation
Step 1
in a square all side are equals, and
in a square, all angles are congruent ( all right angles)
if
angle AEB is rigth, then
[tex]\begin{gathered} m\measuredangle AEB=90 \\ \text{replacing} \\ 3x=90 \\ \text{Divide both sides by 3} \\ \frac{3x}{3}=\frac{90}{3} \\ x=30 \end{gathered}[/tex]
I hope this helps you
