Copy of 14.7b The Inverse of a Rotation
What is the inverse of a rotation by any angle around the point O?
Drag the first slider to rotate triangle ABC.
Then drag the second slider to rotate the image A'B'C' by the angle beta until it coincides with ABC. What is the measure of beta?
Finally, drag the last slider until the image coincides with triangle ABC. What is the measure of delta?
Inverses are unique and "undo" the original rotation. The inverse of alpha is its opposite, or delta.