Question

A 15m 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

as you can see in the triangle ABC
hypotenuse(ladder)=15m

given

one of the sides(distance of window from the ground)=12m

thus in this right triangle,
${12}^{2} + {x}^{2} = {15}^{2}$
${x}^{2} = 225 - 144$
${x}^{2} = 81$
therefore distance between the ladder and the building ie. =x=9m