Scale Factor

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. It is used to determine the proportional relationship between two similar figures.

Front

If two figures are similar, what does that mean?

Back

It means that the figures have the same shape but may differ in size. Their corresponding angles are equal, and their corresponding sides are in proportion.

Front

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

Back

To find the scale factor, divide the length of a side of one figure by the length of the corresponding side of the other figure.

Front

If the scale factor is 3, what does that mean for the dimensions of the figures?

Back

It means that each dimension of the larger figure is 3 times the corresponding dimension of the smaller figure.

Front

What is the scale factor if a rectangle's length is 20 cm and its scaled copy's length is 5 cm?

Back

The scale factor is 0.25 (5 cm / 20 cm).

Front

If triangle ABC is similar to triangle DEF and the length of side AB is 6 cm and side DE is 2 cm, what is the scale factor?

Back

The scale factor is 1/3 (2 cm / 6 cm).

Front

What is the missing side length if triangle ABC has sides 3 cm, 4 cm, and x cm, and triangle DEF has sides 1 cm, 1.33 cm, and 1 cm?

Back

x = 1 cm.

Front

If the scale factor is 2, what happens to the area of the figure?

Back

The area of the figure increases by a factor of 2^2 = 4.

Front

What is the relationship between the scale factor and the perimeter of similar figures?

Back

The perimeter of similar figures increases by the same scale factor.

Front

If a figure is enlarged by a scale factor of 4, how does this affect the dimensions?

Back

All dimensions of the figure are multiplied by 4.