Question

A 20 foot ladder is leaning against a tree. The bottom of the ladder is 12 feet away from the bottom of the tree. Approximately how high up the tree does the top of the ladder reach?

Answer 1

Hey!

The top of the ladder reaches approximately 16 feet up the tree.

Hope this helps!

Answer 2

You will see that the ladder, tree and ground form a right-angled triangle and so we can use Pythagoras' Theorem: c^2 = a^2 + b^2, where c is the hypotenuse (in this case the length of the ladder) and a and b are side lengths (in this case the distance between the tree and the ladder and the height that the ladder goes up the tree)

c^2 = a^2 + b^2
20^2 = 12^2 + b^2
400 = 144 + b^2
b^2 = 256
b = 16 feet