Answer:
x = 20
Step-by-step explanation:
We see that the whole measure angle is equal to 90 degrees. According to Part-Whole-Postulate, if we add the smaller angles, we will get 90 degrees. Knowing this, we can form an equation to find the value of x.
x + 2x + (x + 10) = 90
Now you just solve this equation
x + 2x + x + 10 = 90
4x + 10 = 90
4x = 80
x = 20
