A parallelogram is a quadrilateral with opposite sides that are parallel and equal. The line of symmetry is the imaginary line formed as a result of folding a figure to obtain the symmetrical halves.
Lines of symmetry in a parallelogram are those that divide a parallelogram into two halves, each of which is the mirror image of the other. We know that parallelograms are classified based on their shapes, line segments, and corners. As a result, they have different symmetry lines and a different number of symmetry lines. By folding a shape and looking for the Line of Symmetry, we can determine whether it is symmetrical. If the folded part fits perfectly on top, with all edges and corners matching, the folded line represents a Line of Symmetry, and the shape is symmetrical along its length, breadth, or diagonals.
How to do lines of symmetry
A line of symmetry is a line that exactly cuts a shape in half. This means that if you folded the shape along the line, both halves would exactly match. Similarly, if you placed a mirror along the line, the shape would not change.
A line of symmetry is a mathematical reflection that maps any point on the figure back to the figure.
Take a rectangular piece of paper and fold it in half. Fold it lengthwise once, so that one half fits exactly over the other, and crease the edges. Now open it up and fold it once more along its width.
Symmetry Lines in Various Parallelograms
There are three types of parallelograms, each with a different number of symmetry lines. Below are explanations of the symmetry lines in each of these parallelograms.
How many lines of symmetry is in a parallelogram
A parallelogram, it turns out, does not have any lines of symmetry.
But why don’t parallelograms have symmetry lines? Because it is impossible to construct a line of symmetry for any parallelogram (an axis or imaginary line that passes through the center of the figure and cuts the image in half, where each side is a mirror image of the other).
Draw a line of symmetry on any parallelogram and discover that it is impossible.
We can see from the diagram above that:
- A parallelogram has no line of symmetry along its length or breadth. When folded along its half, there is no superimposition of one half on the other.
- The diagonals are not symmetrical in any way. This is because folding the parallelogram along the diagonal line does not result in the same shape as two halves.
- Thus, parallelograms lack lines of symmetry but have rotational symmetry at 180° about the center.
A Parallelogram’s Rotational Symmetry
Rotational symmetry occurs when an object is rotated in a specific direction, specifically around a point. As a result, rotational symmetry persists when a shape is turned and the shape is identical to the origin. After being rotated around a center point, the figure retains its exact appearance. A parallelogram has no or only one line of symmetry. It has rotational symmetry of order 2 in terms of order.
Different parallelograms have different rotational symmetry orders:
- Square – 4 90°, 180°, 270°, 360°
- Rectangles – 2, 180°, 360°
- Rhombus – 2, 180°, 360°
Conclusion
We learned that, A parallelogram is a simple quadrilateral with two pairs of parallel sides in Euclidean geometry. The symmetry lines in a parallelogram differ depending on the type. In simpler terms, parallelogram lines of symmetry are the lines that divide a parallelogram into two identical parts. To refresh your memory, a parallelogram is a quadrilateral with opposite sides that are parallel to each other. A parallelogram has no lines of symmetry because its opposite or facing sides are of equal length and its opposite angles are of equal measurement. It has order two rotational symmetry.