过O,作AB的平行线,和AD交于F,和BE交于H,
过O,作AD的平行线,和AB交于K,和CD交于G,
根据题意,得
OA/AC=OF/CD=DG/CD
∴OA/OC=DG/CG
同理,
OE/OA=OH/AK=BK/AK
∵AK/CG=KO/GO=BK/DG
∴DG/CG=BK/AK
∴OA/OC=OE/OA
∴OA^2=OC*OE
过O,作AB的平行线,和AD交于F,和BE交于H,
过O,作AD的平行线,和AB交于K,和CD交于G,
根据题意,得
OA/AC=OF/CD=DG/CD
∴OA/OC=DG/CG
同理,
OE/OA=OH/AK=BK/AK
∵AK/CG=KO/GO=BK/DG
∴DG/CG=BK/AK
∴OA/OC=OE/OA
∴OA^2=OC*OE