MN || BC=> ∆AMN asemenea ∆ABC=>AM/AB=MN/BC=AN/AC=>
AM/AB=2/4 il simplificam prin 2=AN/AC=>
=>AM/AB=1/2=AN/AC=>AN=k si AC= 2k
AC-AN=4
2k-k=4
k=4=>AC=2k
AC=2×4
AC=8 (cm)
AN/AC=AM/AB=>4/8 il simplificam prin 4=AM/AB
1/2=AM/AB=> AM= k si AB=2k
AB-AM=8
2k-k=8
k=8=> AB= 2×8=16(cm)
Acum poti afla tu Aria. Succes!