Let AC and CE represent the ladder of length 5.8 m, and A and E represent windows of the buildings on the opposite sides of the street. BD is the width of the street.
AB = 4 m and ED = 4.2 m
In ∆ABC, ∠B = 90° [Given]
AC2 = AB2 + BC2 [Pythagoras theorem]
∴ CD = 4m (ii) [Taking square root of both sides]
Now, BD = BC + CD [B – C – D]
= 4.2 + 4 [From (i) and (ii)]
= 8.2 m
∴ The width of the street is 8.2 metres.