There existsAnd there is How about this adding this command:
It would create the red area below. Yes, there is a workaround, but IMHO a student should be able to use this command to quickly define and find the circular segment of a circle part...This is one of the few parts of a circle where there is no command at this time. The green triangle is also a circle part but is easy to define with the polygon commands.
I hope the developers will add this command to the command list...