Question

The sides of a rectangular park are in the ratio 4:3.If its area is 1728m2,find the cost of fencing it at Rs.30 per metre.

Answer 1

Let the length and width be 4a and 3a respectively

Area = Length × Width

=> 1728 = 4a × 3a

=> 12a^2 = 1728

=> a^2 = 144

=> a = 12

Length = 4 × 12 = 48

Width = 3 × 12 = 36

Perimeter = 2 ( 48 + 36)

= 2 × 84

= 168 m

Cost of fencing = Rate × Perimeter

= 168 × 30

= Rs 5040

Answer 2

hey dear !
here is ur answer
.........
let the length be 4x and breadth be 3x
area of rectangular park =l×b=1728 m^2
4x×3x=1728
12x^2=1728
x^2=1728/12
x=root 144
x=12
therefore length =4x=4×12=48 m
breadth =3x=3×12=36m
cost of fencing it = 1728 × 30= Rs. 51840

hope this will help you :)