posted by Randi .
A 10 ft. ladder is leaning against a building and makes an angle of 65 degrees with the ground. How high above the ground is the top of the ladder?
Draw a right triangle, with 65° with the horizontal.
The ladder is the hypotenuse, and the wall is the opposite side of the 65° angle.
The height of the top of the ladder is therefore
where L is the length of the ladder.