The foot of a 20 ft. ladder is 12 ft. from the base of a house. How far up the side of the house does the ladder reach?

1 Answer
Mar 15, 2016

The ladder reaches 16 feet up the side of the house.

Explanation:

![https://en.wikipedia.org/wiki/Right_triangle](useruploads.socratic.org)

Let c denote the ladder.
c = 20 feet

b denotes distance of the base of the ladder to the house.
b = 12 feet.

we are required to calculate the value of a:

Using the Pythagoras Theorem:
c^2= b^2 + a^2

20^2= 12^2 + a^2

400 = 144 + a^2

400 - 144 = a^2

a^2 = 256

a=sqrt 256

a= 16 feet.