Scale factor lesson 10

Scale factor lesson 10

notes: copy in your notebook

A scale factor is like the constant of proportionality. It’s still $\frac{Y}{x}$   . 

The y, the dependent variable is the model created or drawn and the x ( the independent) is the real life or actual measurement

Multiple Choice

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

• old/ new

• drawing / actual

• Actual / model

Multiple Choice

An area rug is 9 feet wide. In a photograph, the image of the rug is 3 inches wide. What was the scale factor used?

• $\frac{1}{3}$

• $\frac{1}{9}$

• 3

Multiple Choice

The Waccamaw Bridge is 60 meters long. The length of a model of the bridge is 15 cm long. What is the scale of the model?

• $\frac{1}{4}$

• $\frac{1}{15}$

• $\frac{1}{60}$

Multiple Choice

If the original is 12 units and the scale factor is 1/4 what is the size of the scale drawing?

• 300
• 4.8
• 3
• 4

Multiple Choice

Scale: 1cm.=7m The width of the backyard is 49 m, how wide is it in the drawing?

• 14 cm

• 7 cm

• 42 m

• 7 m

Multiple Choice

A blueprint was using a scale of 3cm=4.5 m. Which number represents the dependent?

• 3

• 4.5

• 7.5

• neither

Multiple Choice

The scale drawing car length is 3 cm. If the scale is 1 cm:4 ft, what is the actual car length?

• 12 feet

• 16 feet

• 10 feet

• 4 feet

Multiple Choice

What fraction do we create to find the scale factor.

• $\frac{original\ }{scaled}$

• $\frac{scaled}{original}$

Multiple Choice

What is a scale drawing?

• A drawing that shows a real object enlarged or reduced
• A drawing of the weight of an object
• A life size drawing of an object
• A drawing that shows all the sides of a building

Multiple Choice

To make a toy car, a company made a smaller model of the toy car. They used the scale factor 3cm = 7cm. The model was 18 cm, what was the size of the toy car?

• 126 cm

• 42 cm

• 21 cm

• 54 cm