Question

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

Answer 1

This forms a right-angled triangle with $CB=$ height of the ladder $=17cm$

$AC=$height of building$=15cm$

$AB=$ distance of the foot of the ladder from the building $=x$

Applying Pythagoras theorem

$(AC{)}^2+(AB{)}^2=(CB{)}^2$

$(15{)}^2+(x{)}^2=(17{)}^2$

$225+(x{)}^2=289$

$x^2=64$

$x=8cm$

$AB=$ distance of the foot of the ladder from the building $=8cm$