已知三角形ABC顶点A(2,3,1) B(-1,1,2) C(1,-2,3),求面积

>> sqrt(3^2+2^2+1) %MATLAB运行ans =3.7417>> >> a1=sqrt(3^2+2^2+1)a1 =3.7417>> ac=sqrt(1+5^2+2^2)ac =5.4772>> bc=sqrt(2^2+3^2+1)bc =3.7417>> p=(a1+ac+bc)/2p =6.4803>> s=sqrt(p*(p-a1)*(p-ac)*(p-bc))s =6...