You need to design a rectangle with a perimeter of 14.2 cm. The length must be 2.4 cm. What is the width of the rectangle? (You might want to draw a picture.)

a) Let w = the width of the rectangle. Write the equation you would use to solve this problem.

b) Now solve your equation
* cm.
The width of the rectangle must be. Cm

Part (a)

Explanation:

L = 2.4 = length

W = unknown width

The perimeter of any rectangle is P = 2(L+W)

We replace L with 2.4, and replace P with 14.2 to get 14.2 = 2(2.4+w) which is equivalent to 2(2.4+w) = 14.2

Part (b)

Explanation:

We'll solve the equation we set up in part (a)

2(2.4+w) = 14.2

2(2.4)+2(w) = 14.2

4.8+2w = 14.2

2w = 14.2-4.8

2w = 9.4

w = 9.4/2

w = 4.7

The width must be 4.7 cm.