Scale Factor Perimeter and Area

What is the area ratio of the following rectangles?

• 10/7

• 100/49

• 100/36

• 4/36

A figure is dilated by a scale factor of 4. Which of the following statements about the figure must be true?

• The perimeter and area are both multiplied by 4.

• The perimeter is multiplied by 4 and the area is multiplied by 16.

• The perimeter and area are both divided by 4.

• The perimeter is multiplied by 16 and the area is multiplied by 4.

Find the missing perimeter.

• 15

• 20

• 25

• 30

A rectangular garden is 45 ft wide and 70 ft long. On a blueprint, the width is 9 in. Identify the length on the blueprint. 

• 7 in

• 9 in

• 12 in

• 14 in

• The new perimeter will be 2 times the old perimeter.

• The new perimeter will be 1/2 of the old perimeter.

• The new perimeter will be 3 times the old perimeter.

• The new perimeter will be 4 times the old perimeter.

• The perimeter of the new rectangle will be the same as the perimeter of the original rectangle.
• The perimeter of the new rectangle will be 2.5 times as large as the perimeter of the original rectangle.
• The perimeter of the new rectangle will be 5 times as large as the perimeter of the original rectangle.

How does scale factor change the perimeter?

• by the scale factor

• by the scale factor squared

• by the scale factor cubed

A figure is multiplied by the scale factor 1/4. What will be the change in perimeter?

• The perimeter will be 1/4 the original perimeter.

• The perimeter will be 1/8 the original perimeter.

• The perimeter will be 1/16 the original perimeter

When multiplying by a scale factor the perimeter will multiply by...

• The same scale factor

• The scale factor doubled

• The scale factor squared (to the power of 2)

The original perimeter of a rectangle is 30 cm, if we enlarge it by a scale factor of 4 what is the new perimeter?

• 120

• 480

• 1920