Geometric Rotations

Front

What is a geometric rotation?

Back

A geometric 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 is the center of rotation?

Back

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

Front

What does a 90° counterclockwise rotation about the origin do to a point (x, y)?

Back

The new coordinates after a 90° counterclockwise rotation are (-y, x).

Front

What does a 90° clockwise rotation about the origin do to a point (x, y)?

Back

The new coordinates after a 90° clockwise rotation are (y, -x).

Front

How do you determine the angle of rotation in a geometric transformation?

Back

The angle of rotation is the measure of the turn from the original position to the new position, measured in degrees.

Front

What is the result of rotating a point 180° about the origin?

Back

The new coordinates after a 180° rotation are (-x, -y).

Front

If point A(2, 3) is rotated 90° counterclockwise about the origin, what are the coordinates of A'?

Back

A'(-3, 2).

Front

If point B(-1, 4) is rotated 270° counterclockwise about the origin, what are the coordinates of B'?

Back

B'(4, 1).

Front

What is the effect of a 360° rotation on a figure?

Back

A 360° rotation returns the figure to its original position.

Front

How do you rotate a point around a point other than the origin?

Back

Translate the figure so that the center of rotation is at the origin, perform the rotation, and then translate back.