You are buying a ladder for your 30-foot-tall house. for safety, you would like to ensure that the base of the ladder be placed at least 8 foot from the base of the house. What is the shorest ladder you can buy in order to be able to reach to top of your house?
Pythagorean Theorem:
a^2 + b^2 = c^2
30^2 + 8^2 = c^2
900 + 64 = c^2
984 = c^2
31.37 = c
You'll need a ladder that's at least 32 feet long.