STAAR Review Dilations

Front

What is a dilation in geometry?

Back

A dilation is a transformation that alters the size of a figure but keeps its shape and proportions the same. It is defined by a center point and a scale factor.

Front

What is the scale factor in a dilation?

Back

The scale factor is a number that describes how much a figure is enlarged or reduced during a dilation. A scale factor greater than 1 enlarges the figure, while a scale factor between 0 and 1 reduces it.

Front

How do you determine the scale factor of a dilation?

Back

To determine the scale factor, divide the length of a side of the dilated figure by the length of the corresponding side of the original figure.

Front

What is the center of dilation?

Back

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

Front

Back

Front

What is the algebraic representation of a dilation with a scale factor of 2?

Back

The algebraic representation is given by: (x, y) ⟶ (2x, 2y).

Front

If triangle JKL is dilated to triangle J'K'L' with a scale factor of 3, what is the relationship between their corresponding sides?

Back

The lengths of the sides of triangle J'K'L' are three times the lengths of the corresponding sides of triangle JKL.

Front

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

Back

The angles of a figure remain unchanged during a dilation; only the size of the figure changes.

Front

Back

Front

What is the effect of a dilation with a scale factor of 1?

Back

A dilation with a scale factor of 1 leaves the figure unchanged in size; it remains the same.