已知角AOB=80度,过O作射线OC（不同于OA.OB）,满足角AOC=5/3小于角BOC,求角AOC大小

(1)若OC在∠AOB外部,则∠AOC=(3/5)(∠AOB+∠AOC),
∠AOC=(3/2)∠AOB=120°.
(2)若OC在∠AOB内部,则∠AOC=(3/5)(∠AOB-∠AOC),
∠AOC=(3/8)∠AOB=30°.