Question

The length of a rectangle is twice the width. The perimeter of the rectangle can be expressed as `3* 13.7` What is the width?

Answer 1

The width is 6.85.

Explanation:

The formula for perimeter is `p = 2*l + 2*w` where `p` is the perimeter, `l` is the length and `w` is the width.

For this problem we are told the "length is twice the width" or `l = 2w`. Therefore we can substitute `2w` for `l` in the equation for the perimeter giving:

`p = 2*(2w) + 2w`

For this problem we are also told the perimeter is `3*13.7` which is `41.1` so we can substitute `41.1` for `p` in the equation and solve for `w`:

`41.1 = 2*(2w) + 2w`

`41.1 = 4w + 2W`

`41.1 = 6w`

`41.1/6 = (6w)/6`

`6.85 = 1w`

`w = 6.85`