Question

Express the formula P = 21 2w in terms of length,L. Use the new to find the length when the perimeter is 68 and the width is 13.

Answer 1

• l = P/2 -w
• 21

Explanation:

We know the perimeter formula to be ...

P = 2L +2W

Dividing by 2 and subtracting W lets us write the formula for L:

P/2 = L + W

L = P/2 -W

__

For the given measurements, the length is ...

L = 68/2 -13

L = 21