sinA=√[1-(-3/5)^]=4/5
cosB=√[1-(5/13)^]=12/13
sinC=sin[180度-(A+B)]=sin(A+B)
=sinAcosB+cosAsinB
=4/5(12/13)+(-3/5)(5/13)
=33/65
sinA=√[1-(-3/5)^]=4/5
cosB=√[1-(5/13)^]=12/13
sinC=sin[180度-(A+B)]=sin(A+B)
=sinAcosB+cosAsinB
=4/5(12/13)+(-3/5)(5/13)
=33/65