Question

A firefighter needs to lean a ladder against a wall of a building to reach a window. How far away from the base of the building should he/she place the foot of the ladder? Ladder is 25 feet long, window is 23.8 feet high in the building.

Answer 1

7.7 feet

Explanation:

Let the distance from the base of the building to the foot of the ladder be represented by x. Ladder is 25 feet long, while window is 23.8 feet high.

The length of the ladder, the height of the window and the distance from base of building to foot of ladder describes a right angled triangle.

Thus, applying the Pythagoras theorem;

`(25)^(2)` =
`(23.8)^(2)` +
`x^(2)`

625 = 566.44 +
`x^(2)`

625 - 566.44 =
`x^(2)`

58.56 =
`x^(2)`

⇒ x =
`√(58.56)`

= 7.653

The foot of the ladder should be placed 7.7 feet away from the base of the building.