Answer:
x = 60°
Step-by-step explanation:
A circle, or "all the way around," is 360°
The square represents 90°
360° = 90° + (2x - 10)° + (2x + 40)°
360° = 90° + 2x° - 10° + 2x° + 40°
360° = 2x°+ 2x° + 40° + 90° - 10°
360° = 4x° + 120°
240° = 4x°
60° = x
x = 60°
