Cho tam giac ABC can tai A.tren nua mat phang bo AC ko chua B ve Cx vuong goc voi AC.Tren Cx lay D(D khac C).Goi M la trung diem CD, qua M ke duong thang vuong goc voi AD cat duong thang qua B vuong goc voi AB tai K.Chung minh tam giac KBD can
Cho tam giac ABC vuong can tai A, D la mot diem bat ki tren canh AB. Tren nua mp bo AB co chua diem C, ve tia?
mat phang bo AB co chua diem C, ve tia Bx de goc ABx=135 do. Duong thang vuong goc vs Dc ve tu D cat tia Bx tai E. Chung minh tam giac DEC can
giups mk
cho tam giac abc (goc a=90) . duong thang AH vuong goc voi BC tai H . tren duong vuong goc voi BC tai B lay diem D (khong cung nua mat phang bo BC vs diem A ) SAO CHO AH=BD
a) so sanh hai tam giac AHB va DBH
b)chung minh AB song song DH
c) biet goc BAH=35 , TINH goc ACB
Cho tam giac ABC nhon CAB ( AB>AC ). Tren nua mat phang bo BC khong chua diem A ve tia Cx song song voi AB. Tren tia Cx. Lay diem D sao cho CD=AB
a) Chung minh tam giac ABC= tam giac DCB
b) Chung minh AC//BD
c) Tu A ke AH vuong goc voi BC ( H thuoc BC ) Chung minh AH=DK
d) Goi I la trung diem cua BC . Chung minh I la trug diem cua AD
1 cho tam giac abc can a , goc a bang 40 do lay d khac phia b so voi ac thoa man goc cad bang 60 do goc cad bang 80 do chung minh bd vuong goc voi ac
2 cho tam giac abc vuong can a . d la diem bat ki tren ab. tren nua mat phang bo ab tu c ve tia bx sao cho goc abx bang 135 do. duong thang vuong goc voi dc ve tu d cat bx o e . chung minh tam giac dec vuong can
3 cho tam giac abc can b goc abc bang 80 do , i la diem trong tam giac sao cho goc iac bang 10 do, ica bang 30 do tinh goc abi
4 cho tam giac abc can a co goc a bang 100 do , bc =a, ac =b ve phia ngoai tam giac abc ve tam giac abd can d co goc adb bang 140 do tinh ch vi tam giac adb theo a,b
ve hinh gium minh voi , xin mn day
Cho tam giac ABC vuong can tai A, D la mot diem bat ki tren canh AB. Tren nua mp bo AB co chua diem C, ve tia Bx de goc ABx=135 do. Duong thang vuong goc vs Dc ve tu D cat tia Bx tai E. Chung minh tam giac DEC can
1)cho tam giac ABC co goc A <90 độ ve tia Ax vuong goc voi AB(Ax va AC cung nam trong nua mat phang bo la duong thang AB) tren tia Ax lay diem d sao cho AD=AB.Ve tia Ay vuong goc voi AC(Ay va AB cung nam trong 1 nua mat phang bờ la doan thang AC )tren tia Ay lay diemE sao cho Ae=Ac.Goi M la trung diem cua canh BC .Chung minh rang
a)AM=1/2DE
b)AM vuong goc voi DE
2)cho tam giac ABCgoi M,N lan luot la trung diem cua AB va AC .Chung minh rang MN//BCva MN=1/2 BC
3)cho tam giac ABC vuong tai A , AH vuong goc voi BC. Biet HC-HB=AB.Chung minh rang BC = 2AB
4)tim so nguyen x,y sao cho:x-2xy+y=0
5)cho tam giac ABC co goc A = 60 độ . Chung minh BC.BC=AB.AB+AC.AC-AB.AC
1)cho tam giac ABC co goc A <90 độ ve tia Ax vuong goc voi AB(Ax va AC cung nam trong nua mat phang bo la duong thang AB) tren tia Ax lay diem d sao cho AD=AB.Ve tia Ay vuong goc voi AC(Ay va AB cung nam trong 1 nua mat phang bờ la doan thang AC )tren tia Ay lay diemE sao cho AE=AC.Goi M la trung diem cua canh BC .Chung minh rang
a)AM=1/2DE
b)AM vuong goc voi DE
2)cho tam giac ABCgoi M,N lan luot la trung diem cua AB va AC .Chung minh rang MN//BCva MN=1/2 BC
3)cho tam giac ABC vuong tai A , AH vuong goc voi BC. Biet HC-HB=AB.Chung minh rang BC = 2AB
4)tim so nguyen x,y sao cho:x-2xy+y=0
5)cho tam giac ABC co goc A = 60 độ . Chung minh BC.BC=AB.AB+AC.AC-AB.AC
1)cho tam giac ABC co goc A <90 độ ve tia Ax vuong goc voi AB(Ax va AC cung nam trong nua mat phang bo la duong thang AB) tren tia Ax lay diem d sao cho AD=AB.Ve tia Ay vuong goc voi AC(Ay va AB cung nam trong 1 nua mat phang bờ la doan thang AC )tren tia Ay lay diemE sao cho Ae=Ac.Goi M la trung diem cua canh BC .Chung minh rang
a)AM=1/2DE
b)AM vuong goc voi DE
2)cho tam giac ABCgoi M,N lan luot la trung diem cua AB va AC .Chung minh rang MN//BCva MN=1/2 BC
3)cho tam giac ABC vuong tai A , AH vuong goc voi BC. Biet HC-HB=AB.Chung minh rang BC = 2AB
4)tim so nguyen x,y sao cho:x-2xy+y=0
5)cho tam giac ABC co goc A = 60 độ . Chung minh BC.BC=AB.AB+AC.AC-AB.AC