cho tam giac ABC can tai A , cacnh day nho hon cacnh ben . duong trung truc AC cat BC tai M ten tia doi cua AM lay N sao cho AN=BM CMR: CM=CN
 

tam giac ABC can tai A (BC<AB). đuong trung truc AC cat AC tai M . Tren tia đoi cua tia AM lay diem N sao cho AN=BM. Chứng minh rằng:

a, goc AMC=goc BAC

b,CM=CN

c,muon cm CM vuong goc CN thi tam giac ABC cho truoc cần co them dieu kien gì

1.cho tam giac ABC can tai dinh A, trung truc cua canh AC cat CB tai diem D (D nam ngoai doan BC). tren tia doi cua tia AD lay diem E sao cho AE= BD. chung minh tam giac DEC can.( goi y can chung minh CD = CE)

2. cho tam giac ABC co AB < AC, lay diem E tren canh CA sao cho CE=BA, cac duong trung truc cua cac doan thang BE va CA cat nhau tai I

a)chung minh tam giac AIB = tam giac CIE

b)chung minh AI la tia phan giac cua goc BAC

cho tam giac can ABC co goc A =45do,AB=AC. tu trung diem I cua canh AC ke duong vuong goc voi AC. cat duong thang ac tai M. tren tia doi cua tia AM lay diem N sao cho AM=AN.chung minh goc AMC= ACB.b,tam giac ABM=CAN.c,tam giac MNC vuong can tai A

Cho tam giac abc can tai a . tren canh ab lay diem m tren tia ac lay diem n sao cho bm=cn ,duong thang bc cat mn tai i. chung minh i la trung diem cua mn

cho tam giac abc vuong tai a,co ab=9,bc=15
a) tinh do dai canh ac va so ssanh cac goc cua tam giac abc
​b) tren tia doi cua tia ab lay diem d sao cho a la trung diem cua doan thang bd.chung minh tam giac bcd can
c) goi k la trung diem cua canh bc. duong thang dk cat canh ac tai m.tinh do dai doan thang mc
d) duong trung truc cua canh ac cat duong thang dc tai q.chung minh ba diemb,m.q thẳng hàng
 

cho tam giác abc cân tại a goc a 45 do tu trung diem I cua AC ve duong thang vuong goc voi Ac cat BC o M tren tia doi AM lay N sao cho AN=BM chung minh a, goc AMC=goc BAC b, tam giac ABM= tam giac CAN c, tam giac MNC vuong can tai C

Cho tam giac ABC , AB < AC . AE la tia phan giac cua goc BAC (E thuoc BC) . Tren canh AC lay diem M sao cho AM=AB

a) Chung minh tam giac ABE = tam giac AME

b) AE cat BM tai diem I . Chung minh I la rung diem cua BM

c) Tren tia doi cua tia EM lay diem N sao cho EN=EC. Chung minh tam giac ENB = tam giac ECM

d) Chung minh K,B,M thang hang