Shmoop University
Shmoop: Basic Geometry: Perimeter and Circumference
The geometry resource explores perimeter and circumference. Notes, examples, and practice exercises are included.
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.
Homeschool Math
Homeschool Math: Circles
Lesson presents definitions of terms associated with circles and helps students learn to use a compass to draw circles and simple circle designs.
Mocomi & Anibrain Digital Technologies
Mocomi: What Is Circle?
Discusses the radius, diameter, circumference, and area of a circle.