Hi Pieters, yes like Martin writes Construct > Loft would be the tool for that.

You'd want to draw a circle and a triangle, drag the circle upwards in the Z direction, then select both of them and run Construct > Loft to build the shape. Let me know if you are stuck with this process and I will make an example video for you.

It may be a good idea to browse through the reference section of the help file, especially the Construct section:
http://moi3d.com/3.0/docs/moi_command_reference7.htm#Construct

There are are a lot of images in there that show what each command can do - the one for Loft for example has these example images which are similar to what you're doing:



- Michael