review for 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, using a center of dilation and a scale factor.

Front

What does the scale factor in a dilation represent?

Back

The scale factor indicates how much larger or smaller the figure will be after the dilation. A scale factor greater than 1 enlarges the figure, while a scale factor between 0 and 1 reduces it.

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.

Front

What is the difference between a translation and a dilation?

Back

A translation moves a figure from one location to another without changing its size or shape, while a dilation changes the size of the figure.

Front

What does it mean for two figures to be similar?

Back

Two figures are similar if they have the same shape but may differ in size. Their corresponding angles are equal, and their corresponding sides are in proportion.

Front

If a triangle is dilated by a scale factor of 2, what happens to its area?

Back

The area of the triangle increases by a factor of 4, since area is proportional to the square of the scale factor (2^2 = 4).

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image.

Front

What is a rotation in geometry?

Back

A rotation is a transformation that turns a figure around a fixed point at a certain angle.

Front

What is the result of a translation?

Back

A translation results in a figure that is congruent to the original figure, meaning it has the same size and shape.

Front

How do you find the missing side in similar figures?

Back

To find the missing side in similar figures, set up a proportion using the lengths of corresponding sides.