Online Course Discussion Forum

Need help on II-A 8.20

 
 
Picture of Bober Yang
Need help on II-A 8.20
by Bober Yang - Saturday, November 7, 2020, 11:03 AM
 

I don't know how to get the lenght I only know about the angles there not enough info so can I get some help?

 
Picture of Dr. Kevin Wang
Re: Need help on II-A 8.20
by Dr. Kevin Wang - Saturday, November 7, 2020, 3:10 PM
 

Here is the question:

Suppose equilateral triangle $ABC$ is inscribed in a circle. Let $P$ be on minor arc $\widehat{AB}$ such that $AP = 1$ and $BP = 3$ (lengths of the line segments). Find the distance $PC$.

Watch the recording of the class (I just fixed the incorrect link to the recording).  We spent a significant portion of the class to prove Ptolemy's Theorem.  You can try to use it for this problem.