Problem Jun used 56\,\text{cm}56cm56, start text, c, m, end text of ribbon to go around the edge of a rectangular lid. The lid was 13\,\text{cm}13cm13, start text, c, m, end text long.
What is the width of the lid?

The width of the lid is 15 cm

Step-by-step explanation:

The Perimeter of a Rectangle

Given a rectangle of width W and height H, the perimeter is calculated as:

P = 2(W + L)

Jon used 56 cm of ribbon to go around the edge of a rectangular lid. This means the perimeter is:

2(W + L) = 56

Dividing by 2:

W + L = 28

Since the lid was L=13 cm long, the width is:

W = 28 - 13 = 15

The width of the lid is 15 cm