Question

A 20 ft ladder is leaned against the side of a building so that the base of the ladder is 7ft from the building. How high up the wall does the ladder reach?

Answer 1

I tried this:

Explanation:

Here you get a right triangle and you can use Pythagoras Theorem with the length of the ladder as hipotenuse.
You get:

`20^2=7^2+x^2`

rearrange and sove for the height `x`:

`x=sqrt(20^2-7^2)=18.7"ft"`