In this problem, you must use SohCahToa which basically means:
Sin - opposite over hypotenuse
Cosine - adjacent over hypotenuse
Tangent - Opposite over hypotenuse
So in this picture we have 4 -which is on the opposite side of x - and a 5 -which is the hypotenuse of the triangle. This means we must use sin.
Using a calculator you put in:

Your answer is 53.13 degrees
Answer:
I'm not 100% sure on this but I think it would be C- 8.1
Step-by-step explanation:
Step-by-step explanation:
So the Ap will be x,x+10,x+20,x+30
Sum of the angles of a quadrilateral is 360
x+x+10+x+20+x+30=360
4x+60=360
4x=300
x=75
So the angles are 75,85,95,105