1)∠OGC=∠BGF,∠COG=∠BFC=90,∠GBF=∠OCG,
OC=OB,∠BOE=∠COG=90,△BOE≌△COG,OE=OG
2)成立.∠E=∠G,∠BOE=∠GOC=90,OB=OC,△BOE ≌△GOC,OG=OE