http://www.ck12.org Chapter 12. Rigid Transformations
The pentagon can be rotated 4 times and show rotational symmetry. Because there are 5 lines of rotational symmetry,
the angle would be^360
◦
5 =^72
◦. Note that the 5th rotation would be 360◦and so does not count for demonstratingrotational symmetry.
Example B
Determine if the figure below has rotational symmetry. Find the angle and how many times it can be rotated.
TheNcan be rotated once. The angle of rotation is 180◦.
Example C
Determine if the figure below has rotational symmetry. Find the angle and how many times it can be rotated.
The checkerboard can be rotated 3 times. There are 4 lines of rotational symmetry, so the angle of rotation is
360 ◦
4 =^90
◦. It can also be rotated 180◦and 270◦and it will still look the same.