Test Illustrative 8th grade Math Unit #2 (Dilations)

Front

What is a dilation in geometry?

Back

A dilation is a transformation that changes the size of a figure but not its shape. It involves a scale factor and a center of dilation.

Front

What does a scale factor greater than 1 indicate in a dilation?

Back

It indicates an enlargement of the figure.

Front

What does a scale factor less than 1 indicate in a dilation?

Back

It indicates a reduction of the figure.

Front

If triangle ABC is dilated to triangle A'B'C', what is the relationship between the corresponding sides?

Back

The corresponding sides of triangle A'B'C' are proportional to the sides of triangle ABC.

Front

How do you determine if two figures are similar?

Back

Two figures are similar if their corresponding angles are equal and their corresponding sides are in proportion.

Front

What is the formula for finding the scale factor of a dilation?

Back

Scale Factor = Length of Image Side / Length of Original Side.

Front

If the scale factor from triangle ACB to triangle ADE is 2, what does this mean?

Back

It means that each side of triangle ADE is twice the length of the corresponding side of triangle ACB.

Front

What is the effect of a dilation on angles?

Back

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

Front

If a triangle has sides of lengths 3, 4, and 5, what are the lengths of the sides after a dilation with a scale factor of 3?

Back

The new side lengths will be 9, 12, and 15.

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.