Answer:
x = 20
Step-by-step explanation:
The small square at the vertex indicates a 90º angle
Therefor
x + (3x + 10) = 90
Combine like terms
4x + 10 = 90
Subtract 10 from both sides
4x = 80
Divide both sides by 4
If no units then find the square of 135 to get the answer
B. Linear