Circle: Inscribed and Central Angles

[b]Inscribed and Central Angles in a Circle[/b] Angles ACB and AOB are both subtended by the minor arc AB. What relationship do you think exists between the inscribed and the central angle? [b]What to do:[/b] Check the "Show angles" box to display the measure of angles ACB and AOB. Click and drag points A, B, and C. What hypothesis can you make about the measure of an inscribed angle and a central angle subtended by the same arc? Drag point A or B until the central angle equals 180°. Now drag point C around. What hypothesis can you make about the measure of an inscribed angle subtended by the diameter?