Area of an annulus

This entry briefly explores the area of an annulus. In mathematics, an annulus is a ring-shaped object, which contains a region bounded by two concentric circles. The area is simply the area of the large cirle minus the area of the small circle. We use the areas of the circle. Below is the shape of the annulus.

The area of the annulus is the area between the two ring-shaped shapes as shown above. The space with the dots is the area in subject. The area of an annulus formula is given by:

where:

• R is the radius of the outer circle
• r is the radius of the inner
• π is Pi, approximately 3.142

We can simplify the formula further: