Question

How high up on a wall will a 20-foot ladder touch if the foot of the ladder is placed

4 feet from the base of the wall?

Answer 1

Using Pythagorean theorem

`\\ \rm\longmapsto P^2=H^2-B^2`

`\\ \rm\longmapsto P^2=20^2-4^2`

`\\ \rm\longmapsto P^2=400-16`

`\\ \rm\longmapsto P^2=384`

`\\ \rm\longmapsto P=√(84)`

`\\ \rm\longmapsto P=19.6ft`

Answer 2

Explanation:

by using the pythagoras theorem,

the height of the ladder touching the wall =

√(20²- 4²)

=√ (400-16)

=√384

= 8√6 feet

or 19.6 feet