Texas Instruments
Texas Instruments: Looking at Statistics Through Circles
In this activity, students will measure round objects to determine the circumference and diameter, and use the data to explore geometric concepts of the circle with statistics.
CK-12 Foundation
Ck 12: Elem Math: Identifying Rectangles Squares Circles and Triangles
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview and attempt practice problems on identifying rectangles, squares, circles and triangles.
University of Cambridge
University of Cambridge: Maths and Sports: Olympic Rings
This activity explores shapes and circles by encouraging children to look really hard at something they will see very often in the run-up to London 2012, and is designed to be accessible to primary pupils at Key Stage 1.
Mathigon
Mathigon: Geometry: Circle and Pi: Introduction
This lesson focuses on the characteristics of a circle including similarity, radius, circumference, and Pi. It provides formulas to determine the area of a circle, calculating Pi, and learning exercises throughout.
CK-12 Foundation
Ck 12: Geometry: Angles on and Inside a Circle
[Free Registration/Login may be required to access all resource tools.] Solve problems containing angles on or inside a circle.
Math Open Reference
Math Open Reference: Congruent
Learn about congruent with this handy reference guide. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.8 Circles
Understand circles and their measurement applications.