Line of Symmetry

Definition of Line of Symmetry

Line of symmetry is a line that divides a figure into two congruent parts, each of which is the mirror images of the other.

When the figure having a line of symmetry is folded along the line of symmetry, the two parts should coincide.

Video Examples: Identify Lines of Symmetry


Example of Line of Symmetry

    The dotted line shown in the figure is the Line of Symmetry.
      example of  Line of Symmetry

Solved Example on Line of Symmetry

Ques: Among the dotted lines in the figures, which one is a line of symmetry?

    example of  Line of Symmetry
    Choices:
    A. the dotted lines in Figure 2
    B. the dotted lines in Figure 3
    C. the dotted lines in Figure 1
    D. the dotted lines in Figure 4
    Correct Answer: A

Solution:

    Step 1: Line of Symmetry is a line that divides the figure into two parts, which are mirror image of each other.
    Step 2: Among the choices, the dotted line through the letter M divides it into two parts, which are mirror image of each other.
    Step 3: The lines passing through the letters L, P, and Q do not divide them into two parts that would be mirror images of each other.
    Step 4: So, the dotted line through the letter M is a line of symmetry.