STANDARD G.C.A.2
GEO

a Identify, describe and apply relationships between the angles and their intercepted arcs of a circle.  These relationships that pertain to the circle may be utilized to prove other relationships in geometric figures, e.g., the opposite angles in any quadrilateral inscribed in a circle are supplements of each other.
b Identify, describe and apply relationships among radii, chords, tangents, and secants of a circle.  Include algebraic problems built upon these concepts.