Question

The perimeter of a parallelogram is 30 ft and its length is 5 ft. What is the length of the other side?

Answer 1

`"10 ft"`

Explanation:

In a parallelogram, there are always two pairs of congruent sides.

That is, the perimeter of a parallelogram will always be the sum of twice the length, since there are two lengths, and twice the width, since there are two widths.

Hence the formula: `P=2l+2w=2(l+w)`

Manipulate the perimeter formula, given that `P=30,l=5`.

`P=2(l+w)`

`30=2(5+w)`

`15=5+w`

`w=10`

We can go back and check. If the sides of a parallelogram are `5` and `10`, the perimeter will be `5+5+10+10=30`.