Question

Laura has a 12-foot ladder. The safety instructions recommend the base of the ladder be placed 4 feet from the base of the wall. How high will the ladder be able to reach on the wall? If necessary, round to the nearest tenth.

Answer 1

Answer:  x = 71 degrees. Yes, the ladder meets safety standards

Discussion:

The problem describes a right triangle with hypotenuse 12, the side against the ground is 4, and the angle between those two sides is "x".  For this triangle,

cosx = (side adjacent to angle) / hypotenuse

      =  4                                      / 12

      =   1/3

To find "x" take the inverse cosine of each side to find that :

x  is approximately 70.52 degrees. That's 71 degrees rounded to the nearest degree.

Thank you,