Lines of symmetry
Definition of Lines of Symmetry:
A line of symmetry is a line that divides a shape into two identical halves. If you were to fold the shape along the line of symmetry, both sides would match perfectly.
Shapes with Lines of Symmetry:
Many common shapes have lines of symmetry. For example, a square has 4 lines of symmetry—one through each pair of opposite sides. A triangle can have 1, 2, or 3 lines of symmetry depending on its type (equilateral, isosceles, or scalene).
Identifying Lines of Symmetry:
- To find if a shape has a line of symmetry, you can imagine folding it. If both halves match exactly, it has a line of symmetry.
- Some shapes may have more than one line of symmetry (like regular polygons), while others may have none.
Learn with an example
⌛ Is the dotted line a line of symmetry?
- yes
- no
- Imagine folding this picture along the dotted line.
- The two sides will match up exactly. The dotted line is a line of symmetry.
⌛ Is the dotted line a line of symmetry?
- yes
- no
- Imagine folding this picture along the dotted line.
- The two sides will not match up. The dotted line is not a line of symmetry.
⌛ Is the dotted line a line of symmetry?
- yes
- no
- Imagine folding this picture along the dotted line.
- The two sides will not match up. The dotted line is not a line of symmetry.
Let’s practice!🖊️
