Unit Plan
Khan Academy

Khan Academy: Area and Circumference of Circles Challenge

For Students 6th - 8th
Practice interesting area and circumference problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Unit Plan
Cuemath

Cuemath: Circles

For Students 3rd - 8th Standards
Explore everything about circles. Learn various parts of a circle like a diameter, radius, circumference, circles chord, tangent circles, major arc, segment, sector, and discover other interesting aspects of it. Try your hand at solving...
Website
National Council of Teachers of Mathematics

The Math Forum: Elementary Geometry Circles

For Students 9th - 10th Standards
The Math Forum offers an archive of question and answer sessions on circles and how they relate to geometry.
Handout
Cuemath

Cuemath: Radius

For Students 9th - 10th Standards
This reference tool explores the radius of a circle. Provides definitions, solved examples, and practice questions with answers.