Similar Figures and Scale Factors

Front

What is a scale factor?

Back

A scale factor is a number that describes how much a figure is enlarged or reduced in a scale drawing.

Front

If a scale factor is greater than 1, what does it indicate about the new figure?

Back

It indicates that the new figure is an enlargement of the original figure.

Front

If a scale factor is less than 1, what does it indicate about the new figure?

Back

It indicates that the new figure is a reduction of the original figure.

Front

How do you determine if two figures are similar?

Back

Two figures are similar if their corresponding angles are equal and their corresponding side lengths are proportional.

Front

What is the scale factor if a drawing measures 10 units and the original measures 5 units?

Back

The scale factor is 2.

Front

What is the scale factor if a drawing measures 3 units and the original measures 9 units?

Back

The scale factor is 1/3.

Front

If ΔABC is similar to ΔDEF and the scale factor is 1/2, what does this mean for the side lengths?

Back

The side lengths of ΔDEF are half the length of the corresponding side lengths of ΔABC.

Front

What does it mean for two figures to be proportional?

Back

Two figures are proportional if the ratios of their corresponding side lengths are equal.

Front

If the scale factor from a smaller figure to a larger figure is 4, what is the relationship between their areas?

Back

The area of the larger figure is 16 times greater than the area of the smaller figure.

Front

What is the scale factor from a figure measuring 12 units to a figure measuring 3 units?

Back

The scale factor is 1/4.