Salut,
^ insemna la puterea
4S=a^2sin2B
4S=a^2×2sinBcosB
4S=a^2×2×b/2R×(c^2+a^2-b^2)/2ca
4S=[ab(c^2+a^2-b^2)]/2cR
4S=[ab(c^2+a^2-b^2)]/(2c×abc/4S)
4S=[4S(c^2+a^2-b^2)]/2c^2
2c^2=c^2+a^2-b^2
a^2=b^2+c^2
=> triunghiul.este.dreptunghic
conform.teorema.inversa,Pitagora
Spor!
