Question

A ladder 25 m long reaches a window at a height of 7 m above the ground. Keeping its foot at the same point, the ladder is turned so that it reaches a window 20 m high across the street. Find the total width of the street.

Answer 1

Given,

In △ADC

⇒ AD² + AC² = CD²

⇒ 7² + AC² = 25²

⇒ AC² = 625 – 49

⇒ AC² = 576

⇒ AC = `sqrt(576)` = 24 m

In △BEC,

EC² = BC² + BE²

⇒ 25² = BC² + 20²

⇒ BC² = 625 – 400 = 225

⇒ BC = `sqrt(225)` = 15 m

Now the total width of the street is 24 m + 15 m = 39 m

Hence, this is the required.