Torque from weight on extended leg at 90 degrees

[cmkc109]

Homework Statement

The drawing shows a lower leg being exercised. It has a 49 N weight
attached to the foot and is extended at an angle θ with respect to the
vertical. Consider a rotational axis at the knee.
a. When o
θ = 90.0 , find the magnitude of the torque that the
weight creates

Homework Equations

The Attempt at a Solution

Shouldn't the angle be the force (weight) with respect to r? Here is r with respect to r perpendicular, or did I get the labels wrong? If it is the case, should we solve the angle by 90 - theta?

I get the answer but I don't get the concept. Can someone help me with the labelling?
Great appreciated if you can explain it on the diagram, thanks!

 

[cmkc109]

i 've figured out! don't think i can delete the post..