The length of a rectangle is 8cm more than 3 times it's width. The perimeter of the rectangle is 64cm

The length is 26 cm, and the width is 6 cm.

Step-by-step explanation:

The width is unknown. Let w = width.

The length is 8 cm more than 3 times the width.

length = 3w + 8

The perimeter is 64 cm.

P = length + length + width + width

3w + 8 + 3w + 8 + w + w = 64

8w + 16 = 64

8w = 48

w = 6

The width is 6 cm.

length = 3w + 8 = 3 (6) + 8 = 18 + 8 = 26

The length is 26 cm