Question

The Perimeter of a Rectangular pig pen is 210Ft. The length is 5ft greater then the width. How do you find the Length?

Answer 1

Length = 55 ft

Explanation:

Let length be `L`
Let width be `W`

Perimeter`=2W+2L = 210` ...............................(1)

But we are told that `L=W+5"`.........................(2)

So, as we need to find length we need to 'get rid' of `W`
Rearranging equation (2) we gave:

`W=L-5`

Substitute for W in equation (1) gives

`" "2(L-5)+2L=210.............................(1_a)`

Multiply out the bracket

`" "2L-10+2L=210`

Add 10 to both sides

`" "2L+0+2L=220`

`" "4L=220`

Divide both sides by 4

`" "L=220/4 = 55`