Plz guysl need an answer plz guys

w = 5

Step-by-step explanation:

The whole perimeter is 400 cm

15 + 15 = 30

40 - 30 = 10

10 divided by 2 = 5

Width = 5 cm

Step-by-step explanation:

The total perimeter is 40 cm. The perimeter is all of the side lengths added together, so the formula is: length + length + width + width = perimeter. We already know that the length is 15 cm and the perimeter is 40 cm, so the equation is: 15 + 15 + width + width = 40. Add 15 + 15 to get the new equation: 30 + width + width = 40. Subtract 30 from both sides now to get: width + width = 10. The two widths, need to be the same number, so we need to find out what double pair makes 10. This lucky number is 5. So the width is 5.

Hope it helps!

step-by-step explanation: