Angles Subtended From Common Chord
Inscribed angles E and F end at the same chord CD. They are subtended by the chord CD.
Keep the chord CD constant. Move E and F. Keep them both "above" CD in the same segment. What is true about the angles E and F?
If you want the angles E and F to change degrees, what must you do?
Keep CD constant. Put E in the upper segment above CD and F in the lower segment below CD. Which two statements are true?