题目如图,△ABC\triangle ABC△ABC的角平分线BDBDBD、CECECE交于点OOO.延长BCBCBC至FFF,CGCGCG与BDBDBD的延长线相交于点GGG,且∠A=2∠G\angle A=2\angle G∠A=2∠G,OD:DG=3:4OD:DG=3:4OD:DG=3:4,若△DOC\triangle DOC△DOC的面积为666,CG=10CG=10CG=10,则线段COCOCO的长度为______.知识点:勾股定理、切线的判定章节:未标注