Answer:
x = 5
Step-by-step explanation:
The square mark on one of the angle states that the angle is a right angle, meaning that it is 90°.
If you only include the three angles, 8x - 5, 90°, and 55°, then they are supplementary angles.
Supplementary angles are angles that should add up to 180°.
So the equation is:
8x - 5 + 90 + 55 = 180
Now solve:
8x - 5 + 145 = 180
8x + 140 = 180
8x = 180 - 140
8x = 40
x = 40 ÷ 8
x = 5
