First you will select revolve, then define. Front plane first and then top plane with top plane selected from the drop down menu.
Then you are to put a centerline, now my question is how I activate the blue equal symbol on the centerline?
I did place a centerline in the middle, and then a single line at an angle, then I get a message, see the last picture. I am trying to do a sheetmetal cone with single angled line, then after clicking on the green arrow, you put .1046 in the material thickness box, and 359.95 for the angle so you have a seam.