Lizzie, this formulas below show a very easy way to figure out truncated cones, or "frustums".
2 x Pi x r for the small radius then, 2 Pi x R for the big radius. the height remains the same., (H). To make the big radii to form the truncated cone, a string measured out in length with a pencil, allowing for the pencils point to be the drawing tool, attached to a square, and you will be able to draw the large radii, knowing Large H will always be the same. If you know the diameter you wish, top and bottom, you simple bisect the bottom line by the top line. The result is you have the two sides of a right triangle. The Pythagorean theorem will find the sloping. Of course, when rolled edge to edge, the resulting circle is small. This simple formula never fails. Small of "h" being the side adjacent, regardless of position,, the outside portion dimension of bisected Radius being the Base, and with the 90 degree corner, you can figure out the Hypotenuse, Large of H.
