Answer:
x = 135
Explanation:
The total of interior angles of a 6-sided convex polygon is ...
180°(6 -2) = 720°
Two of the angles are marked as 90°, so the sum of angles is ...
2(90°) +4(x°) = 720°
4x = 540 . . . . . . . . . . subtract 180°, divide by °
x = 540/4 = 135 . . . . divide by 4