A13 foot ladder is leaning against a wall. if the point where the ladder meets the wall is 12 feet above the ground, how far from the base of the wall is the the ladder?

a) 1 foot b) 2 feet c) 5 feet d) 22 feet

I would use the formula a^2 + b^2 = c^2
so your problem would look like this: 
12^2 + b^2 = 13^2
144 + b^2 = 169
subtract 144 from both sides
b^2 = 25
find the square root of 25
b = 5

Your answer is C) 5 feet

Hope this helped! :)