Question

A field 90 m long and 40 m broad is exchanged for a square plot of land of equal area. Find the side length of the square.

• A. 30m
• B. 60m
• C. 3600m
• D. 36m

Answer 1

The correct option is B

60m

Given, length (l) = 90 m
breadth (b) = 40 m

Area of a rectangle of length 'l' units and breadth 'b' units is $l\times b$.
$\therefore$ Area of the rectangular plot = $90\times 40$ = $3600m^2$
According to the question, area of the square plot is same as that of the rectangular plot.
Area of the square plot = $3600m^2$
The area of a square with side length 'a' = $a^2$
Therefore, length of the side of the square
= $\sqrt{a^2}=\sqrt{3600}=\sqrt{36\times 100}$ = 6$\times$10 = 60 m.