Question

A15-m-long ladder is placed againts a wall to reach a window 12 m high .find the distance of the foot of the ladder from the wall.

Answer 1

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15m / |12m
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x
${x}^{2} = {15}^{2} - {12}^{2} = 225 - 144 \\x = \sqrt{81} = 9m$