Question

If the perimeter of a rectangle is 56 cm and the width is 13 cm, what is the length?

Answer 1

Length `l=15`.

Explanation:

Perimeter `p` is a sum of the lengths of all four sides of a rectangle - two sides constituting width (`w`) and two sides constituting length (`l`).

Hence,
`p = 2w+2l`

If `p=56` and `w=13`, we get an equation for `l`:
`56 = 2*13+2l`

Solution to this equation:
`l=15`