Răspuns:
a)
PAOB=AO+OB+AB
AB=14, AO=AC/2=16/2=8
OB=PAOB-AO-AB
OB=31-14-8=9
BD=2•OB=2•9=18
b)
PBOC=BO+OC+BC
BC=17, BO=DB/2=23/2=11,5
OC=PBOC-BO-BC
OC=34-17-11,5=5,5
AC=2•OC=2•5,5=11