I am new to SketchUp.
I draw a circle. But when I try to drag the center up with the Move or Push/Pull command it just draws a cylinder. Even when I use the Alt key as well.
Does anybody know?
Roger
If I’m understanding your question “follow me” tool will get you there.
You can’t drag the center of a circle up using move because there is no geometry there for move to act on, just the circle’s face. And you evidently don’t understand how push-pull works, because it extrudes a face along its normal direction, which in your case will produce a cylinder.
What @tuna1957 showed is probably the easiest way to create a cone, though as usual in SketchUp there are no doubt other ways.
1 Like
Just draw 2 lines through the center of the circle (like diameter)
Draw a circle, push pull up to desired height, scale the top face around center to zero?
Learn the basics:
The Learning Center
The SketchUp You Tube Channel
Both are sponsored by the SketchUp Crew and well worth the time spent there.
Invalid scale!
(BTW. The Vertex Tool by ThomThom “knows” similar feature 
)
1 Like
after " just" : You need to use the Move tool on circle center (endpoint of crossings) and press Alt key to autofold, then, recommended to soften the edges (Eraser tool + Ctrl key) … see my animation just before your post.
Sorry, but I know how to do this. I wrote that you do not need to draw two lines crosswise, but two lines through the center are enough.
Oh, so so sorry, I forgot that I have a “technical dilettance”, therefore I’m drawing longer lines… 
2 Likes
Another simple option for a cone, albiet actually a tapered cylinder, is the move tool with a cardinal point.
There can be benefits to this shape rather than a true cone.
1 Like
And, of course, these is another way using the Follow Me Tool. See this SU file.
Cone with Follow Me tool.skp (41.6 KB)
Fantastic response. Thanks very much everybody!