Question

The area of a square plot of side 80m is equal to the area of a rectangular plot of length 160m. Calculate the width of the rectangular plot and the cost of fencing it Rs.7.50per m.

Answer 1

The area of a square plot with side 80m
= 80²
= 6400m²
Let the width of the rectangular plot = b
The area of a rectangle with length l and breadth b = A = l x b
The area of a rectangle wit length 160 and breadth b = A = 160 x b = 6400

⇒ b = `(6400)/(160)`
= 40m
The perimeter of a rectangle with length l and breadth b = P = 2(l + b)
The perimeter of a rectangle with length 160m and breadth 40m
= P
= 2(160 + 40)
= 2(200)
= 400m
The cost of fencing at the rate of Rs.7.50per m 
= 400 x 7.50
= Rs.3000.