How to sketch on a cone surface?

[wch705]

I have stucked on how to extrude a cylinder(the red drawing) on a cone surface.

I searched around and I knew I have to use a projection but I just couldn't get it working. 

[g-andresen · Accepted solution]

Hi,

What do you want to achieve in the end?

günther

[wch705]

Thank you very much. It is simpler than I thought. I thought I have to project the circule on a plane and do some other stuff to achieve it.