Thread: physics help on pulleys with 2 cables

An assembly shown in the picture, GH , HK, HNL are three cables. the mass of box L is 52Kg,
a) determine the mass of box K in order to make angle theta as 25 degrees
b) determine the reaction forces at supports G and N
c) calculate required cable diameter when tensile strength of the cable is 20MPa

have no clue about this question please help?
diagram in link
http://i1152.photobucket.com/albums/...6/Untitled.png
thankyou

try to draw force diagrams on objects, joints and the pulley from the rope and the gravity, on your diagram itself first.