7.5 Reflections and Line Symmetry key

Name: ______________________
Date: _______________
Math 9 Chapter 7 Similarity and Transformations
Lesson 7.5 Reflections and Line Symmetry
Line Symmetry - _________________________________________________________
If we fold a shape along its line of symmetry, the parts match exactly
Example 1: How many lines of symmetry does this pentagon have?
Also, each point on one side of the line of symmetry
has a ___________________ on the other side of the line.
These two points are the _______________________,
or ______________________ from the line of symmetry.
A line of symmetry is also called a ___________________.
Think of the line as a mirror.
Example 2: Identifying Lines of Symmetry in Tessellations
A tessellation is a pattern or arrangement that covers an area or plane without overlapping or
leaving gaps. It can also be called a tiling pattern.
How many lines of symmetry?
Example 3: Identify the triangles that are related to the yellow triangle by a line of reflection
Example 4: Quadrilateral ABCD is part of a larger shape.
Complete the shape if ABCD is a:
a) Reflection in the horizontal line through 2 on the y-axis.
b) Reflection in the oblique (diagonal) line through (0, 0) and (6, 6).
c) Reflection in the vertical line through 5 on the x-axis.
Label each shape with the coordinates of its vertices
Example 5: Copy each polygon onto grid paper. It is one-half of a shape. Use the given line of
symmetry to complete the shape by drawing its other half. Label the shape with
the coordinates of its vertices.
a) Horizontal line through 1 on the y-axis.
b) Vertical line through 5 on the x-axis.
Assignment: Pages 357 – 359, #1 -6, 8 – 10, AFQ #7, Reflect