Geometry: Dilations

Front

What is a dilation in geometry?

Back

A transformation that alters the size of a figure but not its shape, either enlarging or reducing it.

Front

What does the scale factor indicate in a dilation?

Back

The ratio of the size of the image to the size of the original figure.

Front

If the scale factor is greater than 1, what type of dilation is it?

Back

An enlargement.

Front

If the scale factor is less than 1, what type of dilation is it?

Back

A reduction.

Front

What is the scale factor if a figure is enlarged from a size of 2 to a size of 6?

Back

The scale factor is 3.

Front

What is the scale factor if a figure is reduced from a size of 4 to a size of 1?

Back

The scale factor is 1/4.

Front

True or False: A dilation always produces a congruent figure.

Back

False; a dilation produces a similar figure, not necessarily congruent.

Front

What happens to the angles of a figure during a dilation?

Back

The angles remain the same.

Front

What is the effect of a negative scale factor in a dilation?

Back

It reflects the figure across the origin and changes its size.

Front

How do you determine the scale factor from an original figure to its image?

Back

Divide the length of a side of the image by the length of the corresponding side of the original figure.