Rotations

Front

What is a rotation in geometry?

Back

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

Front

What is the center of rotation?

Back

The center of rotation is the fixed point around which a figure is rotated.

Front

What is the angle of rotation?

Back

The angle of rotation is the measure of the degree through which a figure is rotated around the center of rotation.

Front

What is the algebraic representation for a 90° counterclockwise rotation?

Back

(x, y) ----> (-y, x)

Front

What is the algebraic representation for a 180° rotation?

Back

(x, y) ----> (-x, -y)

Front

What is the algebraic representation for a 90° clockwise rotation?

Back

(x, y) ----> (y, -x)

Front

How does rotation affect the size and shape of a figure?

Back

Rotation preserves the size and shape of a figure; it is a rigid transformation.

Front

What does it mean for a transformation to preserve congruence?

Back

A transformation preserves congruence if the original figure and the transformed figure are congruent, meaning they have the same size and shape.

Front

If a point (a, b) is rotated 90° counterclockwise around the origin, what is the new position?

Back

The new position is (-b, a).

Front

If a point (a, b) is rotated 180° around the origin, what is the new position?

Back

The new position is (-a, -b).