As shown in the figure, it is known that in isosceles △ ABC, ab = AC, P and Q are points on edge AC and ab respectively, and AP = PQ = QB = BC=______ .

As shown in the figure, it is known that in isosceles △ ABC, ab = AC, P and Q are points on edge AC and ab respectively, and AP = PQ = QB = BC=______ .

Let QD = PQ, connect QD, connect QD, BD, set \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\pcq = 80-50 = 30 It is 30 degrees