Frustum of a cone

[skow69]

There have been several requests recently for a way to lay out a template for a cone. Here is the old school, low tech method. All you need is a measuring stick and compass. If it is not clear, please ask.

frustum.jpg

conicalfrustum.gif

1) Draw the vertical origin line.
2) Draw r2 and r1.
3) Draw the diagonal to locate point F.
4) Draw the arcs extended from r2 and r1.
5) Calculate the circumference of the base c2. Divide by 20.
6) Set your compass to the distance c2/20.
7) Walk your compass 20 steps along the arc of r2. This will be the distance c2.
Draw a line from that point through F.
9) The purple area is your template.