期中测试答案一、1.【答案】D2.【答案】D3.【答案】C4.【答案】B5.【答案】A6.【答案】C7.【答案】A8.【答案】A9.【答案】D10.【答案】C11.【答案】D12.【答案】C二、13.【答案】示例:14.【答案】15.【答案】54016.【答案】17.【答案】18.【答案】619.【答案】20.【答案】和三、21.【答案】解:(1)在中,.,是的平分线,.(2),.,.22.证明:,.在与中,.23.【答案】(1)解:.证明:,.(2)证明:,.在和中,.24.(1)证明:在和中,.(2)解:.证明:如图,在上截取.平分,.在和中,.,,,即,.,.25.(1)证明:直线,直线.,.,.又,,,.(2)解:成立.证明:,.,.(3)解:由(2)知,.和均为等边三角形,.,.,为等边三角形.初中数学 八年级上册 3 / 3