Commands to draw elliptical arc.

Is there a command input structure to draw an elliptical arc?
I can draw it using the mouse but I need a higher level of precision than that entry method offers.

Also - same issue - I looked inside the .dxf file and when I changed from a complete ellipse to an arc thereof, only one new parameter appeared.  I realise that there are techniques available to do so but I struggle to understand why two number would be multiplexed into a single number in some way - and what is that way?

Many thanks for any help you are able to give a brand new user.

Ignore second part of post.  Worked it out.  By default, parameter 41 is 0 and parameter 42 is 2PI so arc runs from 41 to 42 AC-wise.

You can use the command line to give precise values. Activate it by clicking into it or hitting the space bar.