Calculator Soup
Calculator Soup: Circle Calculator
Use this circle calculator to find the area, circumference, radius, or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.
Cuemath
Cuemath: Area of a Circle
This mini-lesson explores the area of a circle. Provides a definition, examples, and practice questions with answers.
Math Open Reference
Math Open Reference: Diameter
A complete reference guide to diameters. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Area Enclosed by a Circle
A complete reference guide to the area enclosed by a circle. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.