A ladder that is 21 feet long is propped against a building. The bottom of the ladder was placed 4 feet from the base of the bui
lding. How high up on the building does the ladder reach? Round the answer to the nearest tenth of a foot. a.4.1 feet
b.17.0 feet
c.20.6 feet
d.21.4 feet
Ok, take at look at the picture I attached you. As you can see, the length of the ladder, the distance from the floor to the top of the ladder and the distance from the building to the base of the ladder, together, form a right-angled triangle. So, in order to find how high up on the building does the ladder reach, we need to find the height h using Pythagorean Theorem:
The answer is C.37— following the picture, you know the blue angle and the green angles are supplements (add up to 180) so you add them and set them to 180 and solve. This solves out to be 37