Reflections

The point remains unchanged.

The line is the perpendicular bisector of the segment joining the point and its image.

The point moves parallel to the line.

The image and preimage are the same point.

Each vertex of the polygon is mapped to a new location across the line of reflection, forming a congruent image.

The polygon is rotated around a fixed point.

The polygon is resized to form a similar image.

The polygon is translated to a new position without changing orientation.

Reflection over x-axis: (x, y) → (x, -y)

Reflection over y-axis: (x, y) → (-x, y)

Reflection over y = x: (x, y) → (y, x)

Reflection over y = -x: (x, y) → (-y, -x)

(1, -4)

(-1, 4)

(1, 4)

(-1, -4)

(b, a)

(-a, b)

(a, -b)

(-b, -a)