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When an object (or) shape is rotated around its central point, it looks the same. The rotation can be a complete rotation or a partial rotation with some angle. This concept is called rotation symmetry.
We can observe rotational symmetry around us in many objects like ceiling fans, windmill, wheel etc.
Figure-1
Example:
To understand the concept of rotation, we here have a simple example to understand better hands of a clock.
- We know that the hands of a clock rotate only in one direction and along with a fixed point. This fixed point is the center of the clock.
- This movement of rotation of the hands of a clock is called clockwise rotation.
- When an object rotates in opposite orientation to the hands of a clock, this movement is called anti-clockwise rotation.
Figure - 2
> When an object rotates in the clockwise or anti-clockwise direction, its shape or size doesn't change.
> The rotation of any object happens along with a fixed point (as in the hands of the clock), This fixed point is called the center of rotation.
> And every object rotates with a certain angle along the center of rotation, which is called the angle of rotation.
> We know that one complete turn is a rotation of \(360°\), the one-half turn is a rotation of \(180°\), the one-quarter turn is a rotation of \(90°\).