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笔者有幸参与南京市2015中考数学网上阅卷,对其中第20题有些感触.现结合阅卷过程中的具体情况,谈几点想法,与同行交流.一、试题综述题目如图1,△ABC中,CD是AB边上的高,且AD/CD=CD/BD.(1)求证:△ACD∽△CBD;(2)求∠ACB的大小.
I was fortunate enough to participate in the Nanjing 2015 senior high school entrance examination mathematics online marking, of which some of the feelings of the No. 20. Now combined with the specific circumstances of the marking process, talk a few ideas, exchange with peers. CD is the high side of AB, and AD / CD = CD / BD. (1) Confirmation: △ ACD △ △ CBD; (2) Find the size of ACB.