Question

A 15 m long ladder reached a window 12 m high from the ground on placing it against a wall at a distance a. Find the distance of the foot of the ladder from the wall.

Answer 1

By applying Pythagoras theorem,
$(15)^2= (12)^2 + a^2$
$225 = 144 + a^2$
$a^2 =225 - 144 = 81$
$a = 9\;m$

Therefore, the distance of the foot of the ladder from the wall is $9$ $m$.