On 3/14/2020 12:57 PM, Jordan Brown wrote: > Thanks, all.  Good stuff to chew on. So I chewed.  The truly right answer is Adrian's - use a library - but I wanted to understand the math.  (And Adrian's implementation was too complete to easily extract just the math.) After some chewing, I understand some of the math. Kristian and Parkinbot's answers seemed similar, but even after throwing a fair amount of algebra at them I couldn't make them be the same. I ran some tests, and lo and behold, they aren't the same. Kristian's appears to be the one that I want, the "pointy" answer, the one equivalent to offset(delta=xxx, chamfer=false). Parkinbot's appears to be equivalent to offset(delta=xxx, chamfer=true) or offset(r=xxx).  Those are probably the more useful variants in general, but not for my particular case where I need the points connected by straight lines. Thanks!