reflection(line, Object) or reflection(Point, Object)
Reflects a geometric object over a line or through a point. The latter is sometimes referred to as a half-turn.
eflection(line(x=3),point(1,1)) reflects the point at (1, 1) over the vertical line x=3 to create a point at (5,1).
reflection(1+I, 3-2i) reflects the point at (3, -2) through the point at (1, 1) to create a point at (-1, 4).
reflection — Discussion