it is given in the image i uploaded
L→=r→ × p→[/B]
The Attempt at a Solution
If the angular momentum of a particle is the cross product of the position vector of the particle from the axis and its linear momentum, how can the angular momentum of m1 and m2 be m1vR and m2vR respectively, R is not the position vector, it's just the radius of the pulley. The position vector should be a vector that starts at the axis and ends at the center of mass of m1 or m2, R is not even equal in magnitude to the position vector of m2 or m1.