Word problem help? 4

Question

A ladder is leaning against a building so that the distance from the ground to the top of the ladder is 3 feet less than the length of the ladder. Find the length of the ladder if the distance from the bottom of the ladder to the building is 15 feet

 

The length of the ladder is ___ feet

Answer 1

Hi Samatha,

 

In this case you have a right triangle.

 

One side is the ladder  and we will use x for it's length

 

another side is the wall of the building and it's lenght is x-3

 

and the third side is the ground and that is 15 ft

 

so

 

using the pythagorean theorem

 

x² = (x-3)² + 15²

 

x² = x² -6x + 9 + 225

 

6x = 234

 

x = 39

 

so the ladder is 39 ft long

 

the wall of the building is 36 ft long

 

and the ground is 15ft

 

Hope this helps