Question

A ladder 17m long rests against a vertical wall. The foot of the ladder is 8m away from the base of the wall. How high up the wall will the ladder reach?

Answer 1

So the high of the of the wall will be, 15m

Explanation:

You can use Pythagoras theorem, c^2=a^2+b^2.

Take the length of the ladder as c, the foot of the ladder as (a), and the high of the wall as (b).

So :

c^2=a^2+b^2

(17m)^2= (8m)^2+ b^2

289m^2 = 64m^2 + b^2

289m^2 - 64m^2 = b^2

225m^2 = b^2

`√(225m \:) = b`

15m = b