Designing with Arcs

I frequently incorporate circular arcs in the design process. I’ve found that more complicated shapes can be accurately decomposed into a series of arcs meeting at tangents. The first fact to note, with this in mind, is that for a pair of circles intersecting at a tangent point, both the circle centers and their point of intersection fall on the same straight line. From this fact its possible to lay out arcs that meet as tangents. I use this technique for approximating ellipse and hyper ellipse shapes used in the stool tops and clipboards seen on these pages.