That means if we know the axial velocity and if we know the tangential velocity, then we can calculate beta and we can also see what is the geometric angle of attack, is that clear?. So, now lift and drag will depend on this angle of attack. So, lift will be here and the drag will be like this and the resultant force therefore will be here. There will be some resultant force between lift and drag acting on the propeller blade, is that clear? Now, this if I now compose, I resolve in the axial direction and tangential direction, I will get thrust and torque.