Amongst palms the Corypheae are represented by Sabal and Thrinax, and there is a solitary Za,nza amongst Cycads.
We were asked why the ZA was so worried about forcible removals.
The circumcircle is thus seen Areal to be a 2 yz+b 2 zx+c 2 xy=o, with centre sin 2A, sin 2B, co sin 2C; the inscribed circle is A t (x cot ZA)+ (y cot 2B) nates.