Question

A ladder of 15M long reaches a window which is 9M above the ground on one side of a street. keeping its foot at the same paints. The ladder is turned to other side of the street to reach a window of 12M height. find the width of the street

Answer 1

applying Pythagoras Theorem,

width of street =
$\sqrt{ {15}^{2} - {12}^{2} } + \sqrt{ {15}^{2} - {9}^{2} } \\ = \sqrt{(15 + 12)(15 - 12)} + \sqrt{(15 + 9)(15 - 9)} \\ = \sqrt{27 \times 3} + \sqrt{24 \times 6} \\ = 9 + 12 \\ = 21$
so,the width of street = 21 m ...