Unit 3 Rotations & Dilations Study Guide

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 certain angle in a specific direction.

Front

What does 'counterclockwise' mean in terms of rotation?

Back

Counterclockwise means rotating in the opposite direction to the movement of the hands of a clock.

Front

What does 'clockwise' mean in terms of rotation?

Back

Clockwise means rotating in the same direction as the movement of the hands of a clock.

Front

What is a scale factor in dilation?

Back

A scale factor is a number that scales, or multiplies, the dimensions of a figure during dilation. A scale factor greater than 1 enlarges the figure, while a scale factor between 0 and 1 reduces it.

Front

If a figure is rotated 90 degrees counterclockwise, what is the new position of a point (x, y)?

Back

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

Front

If a figure is rotated 180 degrees, what happens to the coordinates of a point (x, y)?

Back

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

Front

What is the result of dilating a point (x, y) by a scale factor of 2?

Back

The new position will be (2x, 2y).

Front

What is the result of dilating a point (x, y) by a scale factor of 1/2?

Back

The new position will be (x/2, y/2).

Front

How do you determine the direction of rotation from a diagram?

Back

You can determine the direction of rotation by observing the orientation of the figure compared to its original position.

Front

What is the effect of a scale factor of 1 on a figure?

Back

A scale factor of 1 means the figure remains the same size; it does not change.