Equation ：

straight line Equation is: ax+by+cz+d=0

here：

a = (By-Ay)(Cz-Az)-(Cy-Ay)(Bz-Az)

b = (Bz-Az)(Cx-Ax)-(Cz-Az)(Bx-Ax)

c = (Bx-Ax)(Cy-Ay)-(Cx-Ax)(By-Ay)

d = -(aAx+bAy+cAz).