Hello. I just learned torque and i am really confused about one thing. T = r x F. Now in the above Torque, we need to find a perpendicular force part which contributes to the torque compared to the r. Hence: T = r X Fsin(theta). But i get confused in the following example: http://img187.imageshack.us/my.php?image=physicslu1.png Basically i am so confused of how to find r x F (i know you try to find perpendicular but it doesnt make sense because i saw some problems in my book use even cosine). Could anyone please clarify which angle you use (outside / inside) compared to r and whether you need cosine or sin. (In the diagram, if the force was instead pushing up on r, would the same angle be used compared to it pushing down on r? ) You can take clockwise angle or counterclockwise angle. So im lost. THanks for your time!