In △ABC\triangle ABC△ABC, ∠A=45∘,a=10,b=102\angle A = 45^\circ, a = 10, b = 10\sqrt{2}∠A=45∘,a=10,b=102. Find ∠B\angle B∠B.
90∘90^\circ90∘
120∘120^\circ120∘
30∘30^\circ30∘
60∘60^\circ60∘