How it works
A fold line makes two halves that match exactly.
A shape with a fold line has line symmetry.
A rectangle has two fold lines, but its diagonals aren't fold lines.
Worked examples
Do the halves match?
- Cut a rhombus along a diagonal.
- Fold it and the halves land on each other.
- Yes, the halves match.
A fold line
- Fold a rectangle down the middle.
- The two halves match.
- That line is a fold line.
Not a fold line
- Fold a rectangle corner to corner.
- The corners don't land on each other.
- That line is not a fold line.
A taste of the worksheet
These are the first problems of set A. The printable sheet has many more, with an answer key.
- Do the two halves match when you fold on the dashed line?
- Do the halves match when you fold this rectangle on the dashed line?
- When you fold this triangle on the dashed line, do the halves match?
- Which picture shows a dashed line that makes matching halves?
- How many lines of symmetry does a square have? ___