Rotation as Two Reflections
Move around the point of the Red Quadrilateral to make any shape you'd like. You may also move the entire red quadrilateral into any desired position.
NOTE:
The green image is a reflection of the red image over the horizontal line.
The orange image is a reflection of the green image over the diagonal line.
The blue dotted lines are circles centered around the same point.
This visualization should be enough to convince you that any rotation about a point (Red Image to Orange image) is just a combination of two reflections.
BONUS FACT: the angle of revolution is twice the angle of the two reflection lines.