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