Question

A rectangular field is 240m long and 180m broad. In one corner a farm house is built on a square plot of side 40m. Find the area of the remaining portion and the cost of fencing the open sides Rs.25per m.

Answer 1

The area of a rectangle with length l and breadth b = A = l x b
The area of a rectangle with length 240m and breadth 180m
= 240 x 180
= 43200m²
The area of a square plot with side 40m on which the farmhouse is made 
= 402
= 1600m²
The area of the remaining plot
= 43200 - 1600
= 41600m²
The perimeter of a rectangle with length l and breadth b = P = 2(l + b)
The perimeter of a rectangle with length 240m and breadth 180m
= P
= 2(240 + 180)
= 840
The boundary to be fenced
= 840 - 2 x 40
= 760
The cost of fencing 1m = Rs.25
⇒ The cost of fencing760m
= Rs.25 x 760
= Rs.19000.