I am sorry if this has been answered and I am not being able to find.
I have a triangle with vertices at $A(x_1, y_1, z_1), B(x_2,y_2,z_2)$ and $O(0,0,0)$. Now, the triangle is rotated about the fixed origin to another position $A'(x_1', y_1', z_1'), B'(x_2',y_2',z_2'), O(0,0,0)$.
with my little knowledge of Euler's rotation theorem, I think there should be a unique rotation matrix to map these two positions of the triangle but don't know how exactly to calculate the matrix.
Any help with an efficient algorithm to calculate the rotation matrix would be very very helpful.