Masuram si obtinem:
AM=7,75 cm
MB=4,25 cm
AB=12 cm
AM+MB=7,75+4,25=12 cm
Observam ca AM+MB=AB
CM=7,5 cm
MD=3,5 cm
CD=11 cm
CM+MD=7,5+3,5 =11 cm
Observam ca CM+MD=CD
AB=AN+NB
12=4+NB
NB=8 cm
CD=CO+OD
11=5,5+OD
OD=5,5 cm
CM=7,5 cm
CM=CO+OM
7,5=5,5+OM
OM=2 cm