Question

Walls of two building on either side of a street are parallel to each other. A ladder $5.8$ m long is placed on the street such that its top just reaches the window of a building at the height of $4$ m. On turning the ladder over to the other side of the street, its top touches the window of the other building at a height $4.2$ m find the width of the street.

• A. $8cm$
• B. $4.2cm$
• C. $4cm$
• D. $8.2cm$

Answer 1

The correct option is D $8.2cm$

The width of the street would be given by $x+y$ as depicted in the above figure.

In a right angled triangle; ($hypotenus{e}^2=(side1{)}^2+(side2{)}^2$),

Using Pythagoras theorem,

$y=\sqrt{{5.8}^2-4^2}=4.2m$

$x=\sqrt{{5.8}^2-{4.2}^2}=4m$

The width of the street = $x+y=4+4.2=8.2$

The width of the street is $8.2m$