Review on Symmetry:

1) Line Symmetry -

2) When you rotate a figure 360 degrees about a centre of rotation, the order of symmetry will be equivalent to the number of times you get the exact shape.

Rotational Symmetry -

Test yourself:
(complete the test bite and get 10 out of 10)

3) Plane Symmetry -

For more interest, the following are some videos on how to make 3-D snowflakes; getting some sparks on bright ACE ideas?