Răspuns:
tr. QPA ~ tr. BCA
=>QP/BC = QA/BA = PA/CA = QA/AC = PA/AP = 4/9 =>QA/AC = 4/9 =>QA = 4AC/9
CQ = CA + AQ = CA + 4CA/9 = 13CA/9
[tex] \frac{ca}{ \frac{13ca}{9} } = ca \times \frac{9}{13ca} = \frac{9}{13} [/tex]
