What would be the perimeter of a rectangle 9cm 5cm?

The formula for perimeter is P=2XL+2XW which is Perimeter = 2 X length + 2 X Width. We want to replace L and W with the the numbers 9 and 5. I don't know which is which but lets say the 9 is the length and 5 is the width. So the new number sentence would be P=2X9+2X5. So now it's time to solve. 2X9=18. 2X5=10. 10+18=28. Your perimeter would be 28cm. Hope this helped! :)