Think of a ruler as a simple rectangle (a long, thin strip).
- What is a line of symmetry?
A line of symmetry is a line that divides a shape into two equal mirror parts. If you fold the shape on this line, both halves match exactly.
- Check the vertical middle line (along the length):
Draw an imaginary line down the center of the ruler, from top edge to bottom edge (parallel to the shorter sides).
If you fold the ruler on this line, the left half covers the right half perfectly. So this is one line of symmetry.
- Check the horizontal middle line (across the width):
Now draw an imaginary line across the center of the ruler, from left end to right end (parallel to the longer sides).
If you fold the ruler on this line, the top half covers the bottom half perfectly. So this is the second line of symmetry.
- Why diagonals don’t work:
Diagonals are symmetry lines only in a square. A ruler is a rectangle (not a square), so folding along a diagonal will not make both halves match. Hence, diagonals are not lines of symmetry here.
Conclusion
So, a plain rectangular ruler has exactly:
\( ext{Two lines of symmetry}\)
\( ext{(one vertical midline and one horizontal midline)}\)
Match with Options
- 0 – Incorrect (we found symmetry lines).
- 1 – Incorrect (there are two, not one).
- 2 – Correct
- 4 – Incorrect (that would be true for a square, not a typical ruler).