Annulus

Definition Of Annulus

Annulus is the area between the two concentric circles having different radii.

A ring-shaped object is called as 'annulus' in Latin.
Area (A) between two concentric circles with outer radius R and inner radius r is given by, A = Π(R2 - r2).

Examples of Annulus

Two concentric circles with outer radius R and inner radius r are shown in the figure. The region shaded with green color is annulus.

A. 38Π square cm
B. 37Π square cm
C. 36Π square cm
D. 40Π square cm