In mathematics, an area among two concentric circles is known as the annulus. The shape of the annulus in real life is similar to the form of a hardware washer or a ring.
The word "annulus" in maths is driven by the Latin word annulus, which means 'small ring'.
Moreover, the edges of annuals consist of two circles that have the corresponding center.
For more precise understandings, let us check out the diagram listed below:
To know about anticlockwise, you can use our Anticlockwise Definition.
In the above diagram, you can see that two circles have two different radius 'r' and 'R', whereas the center of both circles is equivalent.