Theory:

Our earth spin around its axis every day. This movement causes days and nights.
 
The phenomenon of moving about a centre is called rotation.
 
Rotation:
An object is said to be rotating when it moves about its axis, making a \(360\)\(°\)movement. That is, when an object moves from a position, it takes a complete \(360\)\(°\) shift and comes back to the same position.
While rotating the objects take angular shifts.
Example:
Let us look at the following example.
 
In the example given below, we aim to make the object get back to the origin of its rotation.
 
1.PNG
 
In the above example, the blue line makes a \(90\)\(°\) shift during each rotation.
 
The process of rotation begins at the origin. At the end of \(4\) successful \(90\)\(°\) shifts, the blue line gets back to the source of its rotation.
 
The four \(90\)\(°\) shifts complete a whole \(360\)\(°\) rotation.
 
\(90\)\(°\) \(+\) \(90\)\(°\) \(+\) \(90\)\(°\) \(+\) \(90\)\(°\) \(=\) \(360\)\(°\)
 
In other words, an object would take a complete \(360\)\(°\) rotation to get back to its source of rotation.