cho tam giac abc co ^A=90 do .ke tia phan giac goc B cat AC tai D \(\left(E\in BC\right)\) sao cho BE=BA
a, chung minh DA=DE va DE vuong goc voi BC
b, ED cat BA tai K.chung minh DF = DC
c, chung minh BD vuong goc voi FC
cho tam giac ABC can tai A co A < 90 do, duong vuong goc voi AB tai B va duong thang vuong goc voi AC tai C va chung cat nhau tai M.
a, c/m tgABM = tgACM, AM la phan giac cua goc BAC
b, Qua M ve duong thang song song voi AC, duong thang nay cat AB o D. Tren tia doi cua tia CA lay diem E sao cho CE = DB, c/m tgDBM = tgECM
c, BC cat DM tai F. c/m DF = CE
Cho tam giac ABC co goc B=80 do; goc C=40 do. Tia phan giac cua goc A cat BC o D.
a. Tinh goc BAC, goc ADC
b. Goi E la mot diem tren canh AC sao cho AE=AB. Chung minh: \(\Delta ABD=\Delta AED\)
C. Tia phan giac cua goc B cat AC tai I. Chung minh BI//DE
bai1:cho tam giac abc vuong can tai a. 1 duong thang di qua a khong cat doan bc. bh vuong d,ckvuongd. cmr ah=ck
bai2: cho tg abc vuong tai a. phan giac bd,ce cat tai o.
a,goc boc=?
b,lay m,n thuoc bc s cho bm=ba,cn=ca.cm dm//en
c,goi giao diem an va bd la i.cm tg aim vuong can
giup minh voi. cam on a!
cho tam giac ABC có goc B =2 goc C duong trung truc cua BC cat canh AC tai I.cm BIla tia phan gic cua goc B please help me
cho ΔABC vuong tai A va ABC=60
a, so sanh AB va AC
b, Tren BC lay D sao cho BD =AB. Qua D dung cac duong thang vuong goc voi BC cat tia doi AB tai E. CHung minh ΔABC=ΔDEB
c, goi H la giao diem cua ED va AC. chung minh BH la tia phan giac cua ABC
d,Qua B dung cac duong thang vuong goc voi AB cat duong thang ED tai K vhng minh ΔHBK deu
cho tam giac ABC nhon tia phan giac cua goc B va goc C cat nhau tai I CM: AI la phân giác của góc A
cho tam giac abc vuong can tai a,ab =3 cm .qua a ke duong thang d ko cat canh bc.ke bh vuong goc voi d tai h,ck vuong goc voi d tai k
a) chung minh bh song song ck
b)tinh do dai canh bc va so do g minh
c)chung minh goc hab = goc ack
d)chung minh bh +ck =hk
cac ban thong cam ,t ko viet dc dau
cho Δ ABC vuong tai A co B =60 . tren canh BC lay diem D sao cho BA=BD . TIA phan giac cua B cat AC tai I
a, cm ΔBAD deu
b, cm ΔIBC can
c, CM D la trung diem cua BC
d, cho AB= 6cm . tinh BC va AC