1. Which way is a rotation with a negative angle of rotation ?
Negative rotations are clockwise, positive rotations are anti-clockwise.
2. What is a quarter turn rotation?
A quarter turn rotation is a rotation of 90o (anti-clockwise).
3. How many points are invariant (do not move) under rotations?
There is only one invariant point under a rotation. That is the centre of rotation.
4. Is a rotation an isometry?
Yes. The size and shape of the image and the object remain the same under a rotation.
5. What happens if we rotate an object through an angle of 360o?
We get back to where we started from!
