Răspuns:
AM/AN=4/9
MN/AB=5/11
MB/NB=7/2
NB/AM=2/4
Explicație pas cu pas:
AM/AN=AM/AM+MN=4/4+5
NB=AB-(AM+MN)=11-(4+5)=11-9=2cm
MB/NB=MN+NB/NB=5+2/2=7/2