Rotations on the Coordinate Plane

Horizontal- left and right

Vertical- up and down

A ROTATION of a geometric figure is the turn of the figure

around a fixed point.

Clockwiseused sometimes

Counter-clockwiseused most of the time

90a quarter of a turn

180A straight angle

5

4

3

2

1

-5 -4 -3 -2 -1 -1

1 2 3 4 5

-2

-3

-4

-5

Rotate the figure

clockwise 90 around the origin. (The origin is the

center.)

A

BC B

C A

5

4

3

2

1

-5 -4 -3 -2 -1 -1

1 2 3 4 5

-2

-3

-4

-5

AB

CD

D

CB

A

Rotate the figure 90 counter-clockwise around the origin.

5

4

3

2

1

-5 -4 -3 -2 -1 -1

1 2 3 4 5

-2

-3

-4

-5

A

B C

A

BC

Rotate the figure 180 counter-

clockwise around the origin.

5

4

3

2

1

-5 -4 -3 -2 -1 -1

1 2 3 4 5

-2

-3

-4

-5

Rotate the figure 180 clockwise around

the origin.

A B

CD

C

B

D

A

90˚ Rotation

• The general rule for a 90˚ rotation about the origin is: (X, Y) (Y, -X).

• Where you switch the x and y coordinates and multiply the y by -1.

180˚ Rotation• The general rule for a 180˚ rotation about the origin is: (X, Y) (-X, -Y).

• You multiply each coordinate by -1.

270˚ Rotation

AKA 90 ˚ Counterclockwise

• The general rule for a 270˚ rotation about the origin is: (X, Y) (-Y, X)

• Where you switch your x and y coordinate and multiply the x by -1.