A ladder 17 m long reaches a window of a building 15 m above the ground. Find the distance of the foot of the ladder from the building.

Given: length of ladder = 17 m

Length of building = 15 m

To find: Distance of ladder from building.

Theorem Used:

Pythagoras theorem:

In a right-angled triangle, the squares of the hypotenuse is equal to the sum of the squares of the other two sides.

Explanation:

Let the building be “AB”.

The ladder be “AC”.

Now in ΔABC,

By Pythagoras theorem,

Hypotenuse² = Base² + Perpendicular²

⇒ AC² = AB² + BC²

⇒ 17² = 15² + BC²

⇒ 289 = 225 + BC²

⇒ BC² = 289 – 225

⇒ BC² = 64

⇒ BC = √64

⇒ BC = 8 m

Distance of the foot of ladder is 8 m from the building.