CPM Homework Help : CC2MN Problem 4-139

The area of a rectangle is $42$ cm². If the length and width each grow four times longer, what will the new area be?

Hint:

Make an example of a rectangle with an area of $42$ cm².
Since the area of a rectangle is (base)(height), choose a base and height whose product is $42$ . An example is shown.

A rectangle 6 by 7 centimeters

More Help 1:

Multiply the base and height by $4$ .

A rectangle 24 by 28 centimeters

More Help 2:

Now find the area of the larger rectangle by multiplying the new base and the new height.