The perimeter of a parallelogram is 48, with the length of a shorter side being 10. What is the length of one of the longer sides?

Mar 8, 2018

14

Explanation:

I am going to abbreviate "shorter side" to $s$ and "longer side" to $l$.

The perimeter of the parallelogram is the same as all the sides added together, or the same as this equation:
$l + s + l + s = 48$

We already know that $s = 10$ so let's put that into our equation.
$l + 10 + l + 10 = 48$

Now let's simplify:
$l + 10 + l + 10 = 48 \rightarrow$
$2 l + 20 = 48 \rightarrow$ (I added like terms together)
$2 l = 28 \rightarrow$ (I subtracted 20 from both sides)
$l = 14$ (I divided by 2)