5- Scale Factor

Front

What is a scale factor?

Back

A scale factor is a number that scales, or multiplies, some quantity. In geometry, it is the ratio of the lengths of two corresponding sides of similar figures.

Front

How do you find the missing side length when given a scale factor?

Back

To find the missing side length, multiply the known side length by the scale factor.

Front

If the scale factor from ΔDEF to ΔABC is 2, what does this mean?

Back

It means that each side of ΔABC is twice as long as the corresponding side of ΔDEF.

Front

What are corresponding angles in similar figures?

Back

Corresponding angles are angles that are in the same position in different similar figures and are equal in measure.

Front

True or False: All corresponding angles are congruent in similar figures.

Back

True.

Front

If line CB corresponds with line RQ, what can we say about their lengths?

Back

The lengths of line CB and line RQ are in the same ratio as the scale factor.

Front

What is the relationship between the sides of similar figures?

Back

The sides of similar figures are proportional to each other based on the scale factor.

Front

If HJ is a side length on the original image, how do you find the corresponding side length on the scaled copy?

Back

Identify the side length on the scaled copy that is in the same position as HJ and apply the scale factor.

Front

What is the scale factor if the original side length is 5 and the scaled side length is 10?

Back

The scale factor is 10/5 or 2.

Front

How do you determine if two figures are similar?

Back

Two figures are similar if their corresponding angles are equal and the lengths of their corresponding sides are proportional.