Sibling comments address your question, but it occurred to me that this anecdote (which you may well already know) from Andy Hertzfeld illustrates why fillets a

Sibling comments address your question, but it occurred to me that this anecdote (which you may well already know) from Andy Hertzfeld illustrates why fillets are a vital feature: https://www.folklore.org/StoryView.py?story=Round_Rects_Are_Everywhere.txt https://www.folklore.org/StoryView.py?story=Round_Rects_Are_...