Respuesta :

Answer:

  • l = P/2 -w
  • 21

Step-by-step 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