Understanding Scale Factors

What is a scale factor?

• A measurement of time

• A ratio of side lengths

• A unit of weight

• A type of drawing tool

What is a scale drawing?

• A drawing that is the same size as the original

• A drawing that is always larger than the original

• A drawing that is always smaller than the original

• A drawing that is either enlarged or reduced by a certain ratio

How do you find the scale factor between two similar triangles?

• By adding the side lengths

• By subtracting the side lengths

• By multiplying the side lengths

• By dividing the corresponding side lengths

What does a scale factor less than 1 indicate?

• No change

• An enlargement

• A rotation

• A reduction

What does a scale factor greater than 1 indicate?

• A rotation

• No change

• A reduction

• An enlargement

What is the inverse of a scale factor?

• The same as the original scale factor

• The reciprocal of the original scale factor

• Half the original scale factor

• Twice the original scale factor

How can you verify your scale factor calculation?

• By using a protractor

• By adding the side lengths

• By checking the inverse ratio

• By measuring the angles

In the poster example, what is the scale factor from the drawing to the real poster?

• 1/2

• 1/5

• 1/3

• 1/4

What are the dimensions of the scale drawing in the poster example?

• 7 inches by 14 inches

• 6 inches by 12 inches

• 5 inches by 10 inches

• 4 inches by 9 inches

What are the dimensions of the real poster in the example?

• 20 inches by 45 inches

• 15 inches by 30 inches

• 25 inches by 50 inches

• 10 inches by 20 inches