Ah, I was going to make the joke of the mistake for "not being able to count three", but the hair is better. And although we are having fun with these, maybe there really is 'trichonometry', because in the drilling to extract water or oil a trephine called tricon is used, and I suppose we will have to make some measurement before nailing it. Bah. . . , or not, sure is an error by trigonometry.