Scale Factor, Scale, and Proportions

If you want to find the scale factor from one figure to another, which formula should you use?

If the scale factor is greater than one, the figure will be

• An enlargement

• A reduction

If the scale factor is less than one, the new figure will be

• An Englargement

• A Reduction

The ratio of athletes to non-athletes at Taylor middle school is 3 to 4. If there are 225 athletes, how many non-athletes are there?

• 320

• 12

• 8

• 300

A scale drawing of a billboard uses the scale 4 cm : 9 ft. The length of the billboard in the drawing is 11 cm. How long is the actual billboard?

• 4.9 feet

• 16 feet

• 24.75 feet

• 13.25 feet

If you want to increase a shape by a scale factor of 3.5 what would you do to each side of the shape?

• You multiply each side of the shape by 3.5.

• You add 3.5 to each side of the shape.

• You divide each side of the shape by 3.5.

• You subtract 3.5 from each side of the shape.

A car has a length of 12 feet. The model of the car has a length of 1.5 feet. Determine the scale factor.

• 128

• 3

• 1/8

• 135

A model rocket is built to the scale 1:30, or 1 inch = 30 feet. The actual rocket is 6240 feet tall. How tall is the model rocket in inches?

• 208 in

• 45 in

• 18 in

• 1/4 in

A scale factor is...

• a multiplier that causes an object to grow or shrink and change its shape.

• a multiplier that causes an object to grow or shrink without changing shape.

What is the value of the unknown side?

• 1

• 2

• 3

• 6