A mirror line splits a picture into two halves that match exactly. Paint the missing half, then fold pictures to find their lines of symmetry.
Tap squares on the other side of the mirror to make it match.
A mirror line cuts a picture into two halves that match.
Fold along it and one half lands exactly on the other.
Every square is the same distance from the line on both sides.
A heart: 1 line
A rectangle: 2 lines
A square: 4 lines
A circle: as many as you like
A line that cuts a shape into two halves that match exactly, like a mirror. If you fold the shape along the line, one half lands right on top of the other.
Take one square at a time. Count how far it is from the mirror line, then count the same distance on the other side and colour that square. With a slanted mirror, go straight across the line, corner to corner.
Four: one down the middle, one across, and the two diagonals. A rectangle has only two, because folding it along a diagonal doesn't make the halves match. A circle has as many as you like.
Children spot symmetry in pictures and shapes at about 6 or 7, complete symmetrical pictures with a straight mirror line at about 8 to 10, and use slanted mirror lines and count lines of symmetry at about 9 to 11.