Math 444 Wed. 11/31

Using a straightedge and compass, construct a point C so that AC/AB = 2/5.


In this figure, AB is the diameter of the circle.  If angle BAC = x, what is angle BOC

In this figure, AB is the diameter of the circle.  If angle DAB = y, what is angle DOB?

What is angle DAC?  What is angle DOC?

In this figure, AB is the diameter of the circle.  If angle DAB = y, what is angle DOB?

What is angle DAC?  What is angle DOC?

In general, if points A, C, D are on a circle with center O, what is the relationship between angle DAC and angle DOC?  Careful, which angle DOC do you mean?