Texas Instruments
Texas Instruments: Angles in Circles
The student will use the Cabri Jr. APP to discover the relationship between inscribed and central angles in a circle.
Khan Academy
Khan Academy: Angles in Circles
Practice measuring angles using a circle protractor, solve problems about angles as part of a circle. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Wolfram Research
Wolfram Math World: Central Angle
This page provides a brief definition of a central angle which is illustrated with a drawing. This site also contains related links.