Perimeter and Area with Scale Factor

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

• 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.

A rectangle has a perimeter of 15 inches. An image is created with a scale factor of 2. What is the new perimeter?

• 17

• 60

• 30

• 15

What is one way to determine how much the area would increase using a scale factor of 3?

• take the scale factor and square it to get 3x3=9

• add all of the sides together then multiply by 3

• multiply the area of the smaller rectangle by 3

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

• The same scale factor

• The scale factor doubled

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

  (scale factor x scale factor)

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

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

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

• The area will be 1/16 the original area.

If the perimeter is 8 times bigger, what scale factor was used?

• 64

• 8

• 16

• 4

The area of this rectangle is 90 km². If a scaled copy of this rectangle is made using a scale factor of 5, then what is the area of the copy?

• 210 km²

• 450 km²

• 4500 km²

• 2,250 km²