Check out the following pic:

This is a circle with center C, and PQ is the diameter.
Can I take it as a rule that if the angle QPR = X, then QCR = 2X no matter where R is on the edge of the circle?
I saw an example where this was true, but couldn't find a source to support this rule. So I wanted to make sure.
Thanks for your help.

This is a circle with center C, and PQ is the diameter.
Can I take it as a rule that if the angle QPR = X, then QCR = 2X no matter where R is on the edge of the circle?
I saw an example where this was true, but couldn't find a source to support this rule. So I wanted to make sure.
Thanks for your help.

















