Dilations

Front

What is a dilation in geometry?

Back

A dilation is a transformation that alters the size of a figure but not its shape, using a center of dilation and a scale factor.

Front

What is the center of dilation?

Back

The center of dilation is a fixed point in the plane about which all points are expanded or contracted during a dilation.

Front

What is a scale factor in dilation?

Back

The scale factor is a number that describes how much a figure is enlarged or reduced during a dilation.

Front

If a scale factor is greater than 1, what happens to the figure?

Back

The figure is enlarged.

Front

If a scale factor is between 0 and 1, what happens to the figure?

Back

The figure is reduced.

Front

How do you find the coordinates of a dilated point?

Back

To find the coordinates of a dilated point, multiply the original coordinates by the scale factor.

Front

What is the dilation rule for a point (x, y) with a scale factor k?

Back

The dilation rule is (x, y) -> (kx, ky).

Front

What happens to the shape of a figure during dilation?

Back

The shape of the figure remains the same; only the size changes.

Front

How does dilation affect angles in a figure?

Back

Dilation does not change the measures of angles; they remain congruent.

Front

What is the effect of dilation on parallel lines?

Back

Dilation preserves the parallelism of lines; if two lines are parallel, their images after dilation will also be parallel.