Hi all, I'm a newbie here and sorry for my bad English. I wanna share with you guys 2 formulas I've created luckily on a boring day: 1) Let R be circumscribed circle of triangle ABC, let S be it's area. We have: S=2R^2*sinAsinBsinC 2)Let S be area of triangle ABC, a=BC, b=CA, c=AB. We have:(a+b+c)^2 >= S*12*(3^0.5) Did anyone know these before? If didn't, please reply to me.