Annulus practice problems

An annulus is a planar structure bounded by two concentric circles with different radii r1 and r2. It is a set of points whose distance from the common center S is between r1 and r2 inclusive. The area of the circle is the difference in the areas of the larger circle with radius r2 and the smaller circle with radius r1. In other words, an annulus is the intersection of circles with a common center and different radii.

Direction: Solve each problem carefully and show your solution in each item.

Number of problems found: 46


Do you have homework that you need help solving? Ask a question, and we will try to solve it.



We will send a solution to your e-mail address. Solved problems are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active math competitions such as Mathematical Olympiad, correspondence seminars etc...
See also more information on Wikipedia.