how do i explain how there are 4 lines of symmetry in the Alabama state flag?

Answer 1

http://www.learner.org/courses/learningmath/geometry/session7/part_a/index.html
The above site shows how to determine lines of symmetry.

Fold upper left corner to bottom right corner. That is one line.
Fole upper right corner to bottom left corner. That is line 2.
Now see if you can find the other two.
See the picture of the Alabama flag here.
http://www.learner.org/courses/learningmath/geometry/session7/part_a/index.html