Desenul il faci tu.
paralelogram ABCD
AB=12 cm
BC=18 cm
P ∈ (AD) =) AP = 6 cm
AB ∩ CP = (Q) =) PQ =10 cm
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PC = ?
avem DA ║BC si =) PA ║ BC
mergem in triunghiul BCQ unde avem:
AP/BC=QP/CQ = QA/QB =) 6/18=QP/QP+CP = QA/QA+AB
=) 6/18 = 10/10+CP
18*10=6(10+CP)
180=60+6CP
6CP=180-60 =) CP=20 cm