Explicație pas cu pas:
a) AM = 4 cm, QC = 7 cm
MP || BC => ∢APM ≡ ∢PCQ
PQ || AB => ∢AMP ≡ ∢PQC
=> ΔAMP ~ ΔPQC
b) din a):
[tex]\frac{AM}{PQ} = \frac{MP}{QC} \iff \frac{4}{PQ} = \frac{MP}{7} \\ \implies PQ \times MP = 4 \times 7 \implies \bf PQ \times MP = 28[/tex]