We have already discussed that a square is also a regular polygon because its all sides are of equal length and each of its angles is a right angle (of measure 90°) as in figure.Ī figure bounded by five sides of equal length is called a regular pentagon. Let us now discuss a method of finding lines of symmetry of a regular polygon.Ī triangle whose all sides are of same length and each of its angles measures 60°, is called an equilateral triangle shown in figure. For example, a square is a regular quadrilateral figure. A rhombus is symmetrical about each of its diagonals.Ī closed figure bounded by straight line segments of equal length is called a Regular Polygon.A square has 4 lines of symmetry, namely the diagonals and lines joining the mid-points of its opposite sides.An equilateral triangle is symmetrical about each one of the bisectors of its interior angles.A circle is symmetrical about each one of its diameters.A semicircle has one line of symmetry, namely the perpendicular bisector of diameter PQ.A rectangle has two lines of symmetry, each one of which is the line joining the mid point of opposite sides.Then kite PQRS is symmetrical about diagonal PR. Let PQRS be a kite in which PQ = PS and QR = SR.If one half completely covers the other, we say that the line is the line of symmetry otherwise not. The concept of line symmetry is closely related to mirror reflection. All objects and all alphabets below figure have line symmetry. Retrieved 31 August 2022, from /index.A figure has a line symmetry if there is a line about which the figure may be folded so that the two parts of the figure will coincide. A circle has an infinite number of lines of symmetry.Ĭite this Simulator:.

An equilateral triangle has three lines of symmetry.

An isosceles triangle has only one line of symmetry.

A scalene triangle has no line of symmetry.

A figure may have no line of symmetry, only one line of symmetry, two lines of symmetry or multiple lines of symmetry.We learnt that, A figure has line symmetry if a line can be drawn dividing the figure into two identical parts.Each point on the given figure and its corresponding point on the constructed figure are at the same distance from the line of symmetry.Each part of the constructed figure is equal in measurement to its corresponding part in the given figure.When completing a given figure against a given line of symmetry, make sure that: Thus circle has an infinite number of lines of symmetry.Ī shape may have just one or more than one lines of symmetry. Fold the circle in the middle so that the center of the circle lies on the fold we find that we can fold it in many ways. An equilateral triangle has three lines of symmetry.ĭraw a circle of any radius. It forms in the shape of an equilateral triangle. Again open it and fold it into half (for the fourth time), but this time along the other diagonal, as shown in the figure. Now open out the folds and again fold the square into half (for a third time now), but this time along a diagonal, as shown in the figure.

Fold it into half vertically fold it again into half horizontally. Open it up now and again fold on its width in the same way. Fold it once lengthwise so that one half fits exactly over the other half. Take a rectangular sheet (like a post-card). A kite shape has only one line of symmetry. Place them side by side to form a ‘kite’. Symmetry of Different Geometrical Figures: Fold the paper in different ways to produce two identical halves. On one half-portion, arrange short lengths of string dipped in a variety of coloured inks or paints. This is called ink blot patterns.įold a paper in half. The resulting figure will be symmetric and you make different patterns. Spill a few drops of ink on one half side. You can make different symmetrical figures to understand the concept of line of symmetry. The line symmetry is shown in dotted line. When it happens, the fold, which is the mirror line, is a line of symmetry (or an axis of symmetry) for the picture. If we place a mirror on the fold then the image of one side of the picture will fall exactly on the other side of the picture. We can see that the two halves are mirror images of each other.Įxamples of line symmetry can also be found in many of our ancient and modern buildings. More clearly, suppose we could fold a picture in half such that the left and right halves match exactly then the picture is said to have line symmetry.

Symmetry of Different Geometrical FiguresĪ figure can have line symmetry if a line can be drawn dividing it into two equal halves.

When we see certain figures with evenly balanced proportions, we say, “ They are symmetrical”.

Line of symmetry