12.1. Reflection Symmetry http://www.ck12.org
Example C
Does the figure below have reflection symmetry?
Yes, this figure has reflection symmetry.
Watch this video for help with the Examples above.
MEDIA
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CK-12 Foundation: Chapter12ReflectionSymmetryB
Concept Problem Revisited
The starfish has 5 lines of symmetry.
Vocabulary
Aline of symmetryis a line that passes through a figure such that it splits the figure into two congruent halves.
Reflection symmetryis present when a figure has one or more lines of symmetry.
Guided Practice
Find all lines of symmetry for the shapes below.
Answers:
For each figure, draw lines through the figure so that the lines perfectly cut the figure in half. Figure 1 has eight, 2
has no lines of symmetry, and 3 has one.
Practice
For #1 through #8, determine whether each statement is true or false.
- All right triangles have line symmetry.
- All isosceles triangles have line symmetry.
- Every rectangle has line symmetry.
- Every rectangle has exactly two lines of symmetry.
- Every parallelogram has line symmetry.