Question

A rectangular field is to be fenced on three sides leaving a side of $20$ feet uncovered if the area of the field is $680$ square feet. how many feet of fencing is required.

Answer 1

Area of the rectangular field $=680$ square feet

one side $=20$ feet

other side $=\frac{\text{Area}}{\text{one side}}=\frac{680}{20}=34$ feet [$\because$ Area $=$ One side $\times$ other side]

now fencing is to be done on $3$ sides

i.e. three sides are $34,34,20$ leaving another $20$

so, fencing required $=34+34+20=88$ feet