GM-U3.4a Lesson: Reflective & Rotational Symmetry

Unit 3 Lesson 4a:
Reflective & rotational Symmetry

​Goal:

Students are going to analyze the relationship between rotations and symmetry of geometric figures.

Angle measure that can be used to map figure onto itself.
Formula = 360/ # of vertices.

​Angle of Rotation

The number of times a shape can be rotated around a central point and still appear identical to its original position in a full 360-degree rotation

​Order of Rotation

Concepts:

​Procedures:

1) Determine if the figure is a regular polygon.
2) If so find number of points to determine the order of rotation.
3) Then divide 360 by the order of rotation to find angle of rotation.

Regular or Irregular Polygon?

Order of rotation:

Angle of Rotation:

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​Example 1:

Regular or Irregular Polygon?

Order of rotation:

Angle of Rotation:

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​Example 2:

Regular or Irregular Polygon?

Order of rotation:

Angle of Rotation:

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​Example 3: