A7-foot ladder is leaned against a building in such a way that the bottom of the ladder is 4 feet from the base of the wall. find the angle formed between the ladder and the ground.

a.30

b.35

c.55

d.60

For this the easiest way is to picture the situation. You will notice that you have right triangle in front of you. Length of ladder is you largest side of triangle. Right angle is oposite from it. That means we can use simple trigonometric functions.

Because of the angle we need it is easiest to use cosine function

cos(x) = 

cos(x) = 4/7
x = arccos(4/7) = 55.15 degrees

Answer is C