$$\left. \begin{array} { l } { a ^ { 2 } = b ^ { 2 } + c ^ { 2 } } \\ { - 2 b c c \cos A } \end{array} \right.$$
$$a=sqrt(b*(b+Pr*e^4*sin(e)*c^2*o^2*v*t^2*h^2*r*m*y)),-sqrt(b*(b+Pr*e^4*sin(e)*c^2*o^2*v*t^2*h^2*r*m*y))$$