Sophia Learning
Sophia: Circle Vocab 1
Parts of a circle are defined in this lesson. Take a quiz to assess learning.
Khan Academy
Khan Academy: Introduction to Euclidean Geometry: Language of the Circle
In this video student learn formal definition of a circle including tangent and secant lines, diameters, radii, major and minor arcs.
Loyola University Chicago
Math Flix: Circle Vocabulary
This QuickTime movie provides an opportunity to learn about the vocabulary of a circle. As you watch and listen to the teacher and student interact it helps clarify the thinking behind applying this concept.