How can you determine whether or not a polygon has symmetry?

Answer 1

Look at a shape and see if you can see that two halves mirror each other. To check, get a mirror and put it along this line. If the shape still looks the same using the mirror you have a line of symmetry. You can also trace half of the shape, turn the tracing paper over, put it on the other half of the shape and check it is the same.

Yes another way to do it is think REFLECTION. If they are exactly the same, you have a line of symmetry!

Answer 2

If you can slice it in half and it's the same on both sides, it has symmetry