Unit 3 - Rigid Motions - Rotations

Question 1

Definition of Rotation (3)

Answer 1

1. Turn all points
2. Through a certain direction and angle
3. Around the center of rotation

Question 2

How do you know if a rotation occured?

Answer 2

Pre - image and image are both equidistant from the center of rotation

Question 3

What are two things you need to know to perform a rotation?

Answer 3

1. Center of Rotation
2. Angle of Rotation
   (# of degrees & direction)

Question 4

Formula for 90 degree Rotation

Answer 4

Counterclockwise = (-y, x)

Clockwise = 270 Degree Rotation

Question 5

Formula for 180 degree Rotation

Answer 5

(-x, -y)

Question 6

Formula for 270 degree Roation

Answer 6

Counterclockwise = (y, -x)

Clockwise = 90 degree Rotation

Question 7

Is distance, angle measure and orientation preserved in rotations?

Answer 7

Distance: Yes
Angle Measure: Yes
Orientation: Yes

Question 8

Is rotation a rigid motion and why?

Answer 8

Yes, for distance and angle measure is preserved.