We can solve this problem by correctly analyzing the location
of the points.
If the center of rotation is a point outside the triangle,
then this would mean that there would be quadrant shift (revolution) of the
whole triangle itself. Hence this would mean that the resulting triangle will
not touch the pre-image at any point at all.
If the center of rotation is a point on the perimeter of
the triangle, this would also result in a quadrant shift (revolution) or
movement of the triangle.
Now if the center of rotation is a point inside the
triangle, then this would be a simple rotation on its own quadrant hence the
resulting image will touch the pre-image at more than one point. Hence the
correct points are:
point D and point E
