βθ
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ΪAHC = 90
ΪABD = 30
ΪDBH = 50
ΪDCH = 30@@ΜΖ«
ΪCAD Ν ½x©
DEF Ν³Op`
FEC Ν ΪEFC = 40ΜρΣOp`Ι©¦ιB
½ͺεδv
κΒίι
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ίι
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π
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