The angle is between the moment arm (

**r**) and the force (

**F**) when the two vectors are put together tail to tail. For example, for the tension, \(\displaystyle F_T\) we have the diagram below. The diagram on the left is the physical situation, where the moment arm is drawn out to where the force acts. The diagram on the right is when the tension and moment arm are put tail to tail.

-Dan