Transformation involves changing the position of a shape.
The transformation from to
is 90 degrees clockwise rotation
Using the coordinates of A and A', we have:
Notice that the x-coordinate is <em>negated </em>and then <em>swapped </em>with the y-coordinate.
i.e.
The transformation of a point from <em>(x,y) to (y,-x)</em> is a 90 degrees clockwise rotation.
Hence, the transformation from to
is 90 degrees clockwise rotation
Read more about transformations at: