3 Tutor System
Starting just at 265/hour

# Q.3 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.

Here, the ladder forms a right angled triangle.
$$\therefore$$ $$a^2 + 12^2 = 15^2$$(By Pythagoras property)
Or, $$a^2+ 144 = 225$$
Or, $$a^2 = 225 – 144$$
Or, $$a^2 = 81$$
$$\therefore$$ a = $$\sqrt{81}= 9$$ m
Thus, the distance of the foot from the ladder = 9m