1. Advanced Geometry Rigid Transformations Lesson 2
Reflections

2. Reflection Line of Reflection flip

3. Pre-image
Image N E
E  N P P T A A T

4. Example:
Draw the reflected image of quadrilateral WXYZ
in line p.

5. Example:
Name the image of each figure under a
reflection in line F D
trapezoid FHGA

6. Example:
Quadrilateral ABCD has vertices A(1, 1), B(3, 2),
C(4, -1), and D(2, -3). Graph ABCD and its image
under reflection in the x-axis.

7. Example:
Triangle RST has vertices R( -1, 3), S(-5, -2),
and T(2, 4). Graph RST and its image under
reflection in the y-axis.

8. origin, reflect over both the x-axis AND
Example:
Quadrilateral RUDV has vertices R(-2, 2), U(3, 1),
D(4, -1), and V(-2, -2) and is reflected in the origin.
Graph RUDV and its image.
To reflect
in the
origin, reflect over both the x-axis AND
y-axis.

9. Example:
Triangle XYZ has vertices X(4, -2), Y(2, -3),
and Z(3, -5). Graph XYZ and it image under
reflection in the line y = x.

10. Example:
Rectangle JKLM has vertices J(0, 2), K(0, -2),
L(3, 2), and M(3, -2). Graph JKLM and its
image under reflection in the line y = -x.

11. If a figure can be folded so that the two halves
match exactly, the fold is called a line of symmetry.
For some figures, a common point of symmetry,
called a point of reflection, exists
for all points on a figure

12. Determine how many lines of symmetry the figure
Example:
Determine how many lines of symmetry the figure
has and draw them. Then determine whether the
figure has point symmetry.
A point of symmetry is the midpoint of all line
segments joining opposite points of the figure.