Question

The sides of a rectangular park are in the ratio $4:3$. If its area is $1728m^2$, find the cost fencing it at $Rs.30$ per meter.

Answer 1

Length of the rectangular park$=4x$ and Breadth of the rectangular park$=3x$

Area of the rectangular park$=l\times b$

$\Rightarrow 1728=4x\times 3x$

$\Rightarrow 12x^2=1728$

$\Rightarrow x^2=\frac{1728}{12}=144$

$\Rightarrow x=12$ m

$\therefore$ sides of the rectangular park are

Length of the rectangular park$=4x=4\times 12=48$ m and

Breadth of the rectangular park$=3x=3\times 12=36$ m

$\therefore$ Perimeter of the land$=2(l+b)=168$m

Cost of fencing a land per meter$=$Rs.$30$

Cost of fencing a land of $168$m$=$Rs.$30\times 168=$Rs.$5,040‬$