solutions of T^27 ...:
r: 3.63038870001240393968, r/4: 0.907597175003100984920; 4R: 5.91894471315294436554, R: 1.47973617828823609139
r: 3.84761066117936762180, r/4: 0.961902665294841905451; 4R: 7.10888647766239522520, R: 1.77722161941559880630
r: 3.93759646668634517776, r/4: 0.984399116671586294439; 4R: 7.62947300108809949374, R: 1.90736825027202487344
r: 3.97778435073700212028, r/4: 0.994446087684250530070; 4R: 7.86719963949418925991, R: 1.96679990987354731498
r: 3.99758490012541961884, r/4: 0.999396225031354904709; 4R: 7.98551523345992191120, R: 1.99637880836498047780