Question

The length of a rectangle is twice its width. The perimeter of the rectangle is 30 cm. What are the length and width? a) Set up the variables: Let ______ represent the width; Then_____ will represent the length. b)What is the equation that represents the above situation? c)solve the equation d)the length and width are?

Answer 1

• 10 cm and 5 cm

Explanation:

a) Set up the variables:

Let x represent the width; Then 2x will represent the length.

b) What is the equation that represents the above situation?

Use perimeter formula:

• P = 2( l + w)

As we set up w = x and l = 2x, and we know that the perimeter is 30 cm, we can build an equation by substituting the values we know or set up:

• 30 = 2( 2x + x)

c) solve the equation

• 30 = 2( 2x + x)
• 30 = 2(3x)
• 30 = 6x
• x = 30/6
• x = 5

d) the length and width are?

• The width is 5 cm and the length is twice the width, 5*2 = 10 cm