how high is the ladder?

Question

A 17
?-foot
ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 7

feet from the base of the building. How high up the wall does the ladder? reach?

Answer 1

First, draw a picture.

This is a right triangle.  The hypotenuse is 17 ft.  The short leg (the ground) is 7 ft – now, how would I know that this is the short leg?  Because of the Pythagorean Theorem.  17^2 = 289 and 7² = 49, so, x² = 289-49 = 240

x² = 240

x = 15.49

The ladder extends 15.5 feet up the wall.  (p.s., my ruler doesn't have 1/100 of an inch, so I rounded)