Question

The dimensions of a 7 -cm by 2 -cm rectangle are multiplied by 3 . how is the area affected ?

Answer 1

Let's figure this out by first finding the dimensions of the original rectangle, and then finding the dimensions of the new rectangle.

Original rectangle:  Since the area of a rectangle is the length * width, the area of this rectangle is 7 * 2 = 14 square cm.

New rectangle: The new dimensions of this are 7*3 = 21 cm by 2*3 = 6 cm.  To find the area, we multiply these two together.  21*6 = 126 square cm.

126 is 9 times greater than 14, so the area will be multiplied by 9.