Răspuns:
a) AD² = BD*DC BD= AD²: DC= 8,4² :9,8= 70,56 :9,8=7,2
BC=BD+DC= 7,2+9,8=17
AB²=BD *BC= 7,2*17=122,4 AB= [tex]\sqrt{122,4}[/tex]=11,063
AC²= DC*BC= 9,8 *17= 166,6 AC=[tex]\sqrt{166,6}[/tex]=12,907
c) AB= 12 dm =120 cm
BC=AB² : BD= 120*120 : 72=200
DC=BC- BD=200-72=128
AC² = BD* BC= 128*200=25600 AC= 160
AD² = BD*DC=128 *72=9216 AD=96
