Identify and describe relationships among inscribed angles, radii, and chords. Include the relationship between central, inscribed, and circumscribed angles; inscribed angles on a diameter are right angles; the radius of a circle is perpendicular to the tangent where the radius intersects the circle.
Tangent Lines and the Radius of a Circle
Right triangles inscribed in circles I
Right triangles inscribed in circles II
Neglecting the Curvature of the Earth