Circle $P$ has diameter $CD$. Point $B$ is on the circle such that $m\angle BPC=30$ degrees. Point $A$ is on the circle such that $AD$ is parallel to $PB$.
What is the degree measure of arc $ABC$?
I am stuck on how to draw this diagram and go about solving the problem. Do realise the answer must be $60$ degrees, but don't understand how. Any help will be appreciated.
This is my attempt at the drawing:
From the information in the comments, we find that $\angle PAD = \angle ADP = 30º$ ($PA=PD$ since they are both radii, so $\Delta PAD$ is isosceles. Therefore $\angle PAD = 120º$ which gives $\angle APC = 60º$.
This can also be found using the exterior angle theorem, which in this case, means that $\angle PAD + \angle ADP = \angle APC$.
Just to clarify, 'degree measure' means the angle of rotation from one side to the other side, not the angle in between the arc. This is further explained in this YouTube video.