Question

The length and the breadth of a rectangular field are in the ratio 7:5 and its area is 4235 m². Find the cost of
fencing it at the rate of 80 per metre.​

Answer 1

Step-by-step explanation:

Let x be the ratio constant,

Therefore, sides will be 7x and 5x

Area of Rectangular field= 4235 m²

Now,

Area is Rectangular field= 7x x 5x

4235= 7x x 5x

4235=35x²

x²= 4235/35

x²=121

x= 11

Therefore sides are,

Length=7 x 11= 77m

Breadth=5 x 11=55m

Now,

Perimeter of Rectangular field= 2 x length + 2 x breadth

= 2 x 77 +2 x 55

= 154 + 110

= 264m

Therefore, cost of fencing= 264 x 80

= Rs21,120