AB||CD⇒ΔAOB~ΔCOD⇒[tex] \frac{AB}{DC}= \frac{AO}{OC}= \frac{OB}{OD}
[/tex]⇒[tex] \frac{AB+DC}{DC}= \frac{AO+OC}{OC}= \frac{BO+OD}{OD} [/tex]
Dar noi stim ca AO+OC=AC=20cm
iar BO+OD=BD=24 cm
Atunci vom avea:
[tex] \frac{40}{25}= \frac{20}{OC}= \frac{24}{OD} [/tex]
Deci vom avea:
[tex]OC= \frac{25*20}{40}= \frac{25}{2}=12,5 cm [/tex]
[tex]OD= \frac{25*24}{40}=15 cm [/tex]
OA=AC-OC
OA=20-12,5⇒OA=7,5 cm
OB=BD-OD
OB=24-15⇒OB=9cm