Video: Circles: Radius, Diameter and Circumference
Video: Area of a Circle
Video: Inscribed and Central Angles
Video: Perpendicular Radius Bisects Chord
Video: Right Triangles Inscribed in Circles (Proof)
Video: Area of Inscribed Equilateral Triangle (some basic trig used)
Practice with ARCS:
Circles and arcs Relate the length of an arc to the circumference of a whole circle.
Areas of circles and sectors Relate the area of a sector to the area of a whole circle.