I am new to autocad and mostly teaching myself.  Trying to determine angle between two lines.  Can't understand instructions in HELP.  I want to use the Cal command.  It asks for an expression such as "ang(apex, p1,p2), where this would calculate the angle between two lines joining at an apex and terminating at p1 and p2.  Nowhere in the HELP info does it illustrate exactly how to enter the expression.  No example is given.  Can someone give me a "cookbook" example that I can follow to calculate the angle between two lines.  I have Autocad LT 2008.

Easiest way is make made an angle dimension.