Rotation through 90 degrees - anticlockwise

This sheet enhances the concept of rotation. The rigid body to be rotated is a triangle. Rotating the three corners of the triangle is sufficient to rotate the whole of the object (the triangle). The distance from the centre of rotation to the points of interest (the corners of the triangle) of the object and the corresponding point of the image are equal, and rotating it through an angle of (90 degrees in this case) will locate the position of the image, and since it is a rigid body all the regions bounded by the corners of the triangle will have been moved from the object position to the image position.

The above note is for the teacher but the worksheet is simply to enhance the understanding of the concept of rotation and it is left for the pupil to summarise their observations.