Angles Inscribed in a Semicircle Conjecture

The applet below illustrates properties that involve the angles and arcs of circles that must always hold true. Notice Segment AB is the diameter of the circle. Move the red X to change the size of the circle. Click on the box by "Angle ACB". Click on the play button (bottom left corner) to animate the applet. Then answer the question that follows.

Angles inscribed in a semi-circle are __________________.

Tick all that apply