Inscribed Angles

Kim Hager

Vocab Review

To inscribe means to write on something, or to draw something so that the boundaries touch but don't intersect. We have rings inscribed with something meaningful. Above, the One Ring to Rule Them All from the Lord of the Rings is inscribed. Notice that the inscription doesn't extend past the ring. An inscribed angle is one whose endpoints and vertex are all on a circle.

As you move point D from B to C, what do you notice about the value of angle BDC?

As you move point C, what do you notice?

How do you think that the values of angle BAC and angle BDC are related?

Make angle BAC into a straight angle. What can you say about segment BC? What do notice about angle BDC?

What do you wonder about the figures in the applet?

Consider this picture:

Consider this picture:
How many inscribed angles can you find? How many central angles are there? How many radii do you see? How many chords do you see?

After checking your answers and sharing with a classmate, but before going on to the next worksheet, please complete one module in Khan Academy: