Scale Factor Geometry

Scale factor is the number that you _______ by to calculate a measure of a similar figure.

• add

• subtract

• multiply

• divide

If the linear scale factor is 4, what is the area scale factor?

• 2

• 8

• 16

• 25

A scale factor of 1/2 is used to change the dimensions of a rectangle with a length of 7 centimeters and a width of 5 centimeters. What is the perimeter of the resulting rectangle?

• 12 cm.

• 35 cm.

• 24 cm.

• 38 cm.

A scale factor of 2 is used to enlarge the dimensions of a square. What is the effect of this change on the area of the square?

• The area will be half as big.

• The area will be twice as large.

• The area will be 4 times larger.

• The area will be 8 times larger.

• The area will not change.

The dimensions of a rectangular photo are 3.5 in. x 5 in. The dimensions of the photo are enlarged by a scale factor of 2.5. What is the perimeter of the new photo?

• 17.7 in

• 8.75 in.

• 42.5 in.

• There is not enough information to tell.

Stefano holds up an 8-inch pencil 32 inches from his eye. The pencil fills the image of a sculpture that is 40 feet away. How tall is the sculpture?

• 10 ft.

• 8 ft.

• 22 ft.

• 14 ft.

• 16 ft.

• 18cm

• 12cm

• 14cm

• 24cm

• 100cm²

• 16cm²

• 90cm²

• 30cm²

• 40

• 10

• 5

• 25

• 81

• 4.5

• 3

• 9