Question

the length of the rectrangular field is twice its breadth ifvthe are of the field is 3200 square meters what is the cost of fencing the field at rs 40 per meter​

Answer 1

Explanation:

Area of a rectangle = Length x Breadth.

Area= L x B

We are told the length is twice the breadth.

You can write this as :

Length = 2 x Breadth

L = 2B

If you put that into the area formula at the beginning, we get:

Area = L x B

Area = 2B x B =
`2B^2`

They also told us that the area of the field is 3200 square meters. So,

Area =
`2B^2` = 3200

Divide both sides by 2

`B^2`=
`(3200)/(2) = 1600`

Now to solve for B we need to square root both sides.

`B = √(1600)` = 40

So now we know the Breadth is 40meters

Remember earlier we said Length = 2 x Breadth

`L = 80`

Cost of fencing the field = 2L + 2B

Cost of fencing the field = 2 x 80 + 2 x 40 = $240