This math topic centers on calculating the area of a "circle donut" or annulus using both the inner and outer radii of the shape. Students are required to determine the area to the nearest integer. It is an introductory geometry task that falls within the study of circle areas, sectors, and donuts. The exercises involve a specific focus on the mathematical procedures needed to subtract the area of the smaller inner circle from the larger outer circle, using the formula for the area of a circle, πr². Each question presents unique radii measurements and multiple-choice answers.
Work on practice problems directly here, or download the printable pdf worksheet to practice offline.
Complete these online problems with 80% or 4 correct answers in a row. Results are immediate.
Find the area (to the closest integer) of the donut with outer radius 9 and inner radius 8