Rotations and Dilations Review

Front

What is a rotation in geometry?

Back

A rotation is a transformation that turns a figure around a fixed point, called the center of rotation, by a specified angle in a specified direction.

Front

What are the coordinates of a point after a 180° rotation about the origin?

Back

If a point has coordinates (x, y), after a 180° rotation about the origin, the new coordinates will be (-x, -y).

Front

What is dilation in geometry?

Back

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 a scale factor of 3 mean in dilation?

Back

A scale factor of 3 means that each coordinate of the original figure is multiplied by 3, resulting in a figure that is three times larger.

Front

If triangle ABC has vertices A(2, 3), B(4, 5), and C(6, 7), what are the coordinates after a dilation with a scale factor of 2?

Back

A'(4, 6), B'(8, 10), C'(12, 14).

Front

What is the effect of a 270° counterclockwise rotation on a point (x, y)?

Back

The new coordinates will be (y, -x).

Front

True or False: A dilation produces a congruent figure.

Back

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

Front

What are the coordinates of point B(3, 4) after a 90° clockwise rotation about the origin?

Back

B' (4, -3).

Front

How do you find the image of a point after a rotation?

Back

To find the image of a point after a rotation, apply the rotation rules based on the angle and direction of rotation.

Front

What is the center of dilation?

Back

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