Query: Describe fully the transformation which takes shape A onto shape C. [Please click on the graphic to see the full size question].
Response: It can be seen that the shape A has been turned to arrive at position C, so a favoured method is to use tracing paper to investigate it further.
Proceed as follows: Trace the shape A and place it directly over A. Now put your pencil point on the point (0,0) and rotate the paper. Does the shape A cover position C? In this case it does, but in another question you would have to try other 'centres' with your pencil point, until one works.
You'll see that the transformation which maps A onto C is a clockwise rotation of 90o centered at the origin (0,0).