Draw a square. How many lines of symmetry does it have? Draw them.

A square has 4 lines of symmetry: one vertical, one horizontal, and two diagonal.

The letter 'O' has infinite lines of symmetry. Explain why.

Any line that passes through the center of the 'O' will create two matching halves.

I can identify lines of symmetry in two-dimensional shapes.

1
If you cut an image in half along a line, the two halves will be mirror images of each other; this is called line symmetry.
2
An image that has symmetry is called symmetrical, and an image that does not have symmetry is called asymmetrical.
3
Rotational symmetry means that if you rotate a shape the right amount, the rotated shape will match the original shape.