Point of Symmetry

Definition of Point of Symmetry

If a figure or graph is rotated about a point by 180� and yet looks identical to its original, that point is called the Point of Symmetry.

More About Point of Symmetry

    If a figure has a point of symmetry, then its order of rotational symmetry will be 2.

Video Examples: Polar Axis Dialog


Example of Point of Symmetry

    The point of intersection of two lines x � y = 0 and 3x � 10y = - 14 is given below.
       example of  Point of Symmetry
    In the figure, a rectangle is rotated 1800 by a point.
    The rectangle obtained after rotation matches with the original rectangle.
    So, the point with which the rectangle is rotated is called the point of symmetry.

Solved Example on Point of Symmetry

Ques: Which of the figures has a point of symmetry?

     example of  Point of Symmetry
    Choices:
    A. Graph 1
    B. Graph 2
    C. Graph 3
    D. none of the above
    Correct Answer: A

Solution:

    Step 1: A figure or a graph when rotated by 180� looks similar to its original, it is said to have a point of symmetry.
    Step 2: When Graph 1 is rotated through 180�, it matches the original figure.
    Step 3: So, Graph 1 has point of symmetry.

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