Then △ aqp △ dqp

Find ∠ qap = 75, ∠ aqp = 30,

So ∠ QPA = 75,

∠QAP=∠QPA

AQ=QP，

∫AQ = AD = AB，PQ‖AB

PQ‖ and =AB

AQPB is a parallelogram,

So BP = AQ = BC, (likewise PC = BC)

BP=BC=PC

Draw a conclusion.

~ ~ Teacher Da Dan has come to visit. O(∩_∩)O ha!