cho tam giac abc co goc a bang 90 do. bd la phan giac cua goc b ve de vuong goc bc .goi f la giao diem cua ab va de 

a, chung mijh tam giac _{abd = tam giac ebd va duong trung truc cua ae}

_{b, chung minh tam giac dcf can}

_{c,  khi tam giac abc co goc b bang 60 do , c = 30 do va bc = 12 cm . tinh do dai dc}

BAI 1

a,CHO TAM GIAC ABC CO CANH AB= 4CM ; AC =5 CM BC =6CM SO SANH CAC GOC ABC

b, CHO TAM GIAC ABC CO GOC A = 80 DO GOC B =65 DO HOI CANH NAO NHO NHAT

tim tat ca cac canh va goc chua biet cua tam giac vuong do, cho tam giac abc vuong tai a co: b) BC=12, goc B= 35 do.

c) AC=4, goc C=42 do,

d) AB=15, BC=25

e) AB=6, goc C= 60 do

cho tam giac ABC co AB=6cm,AC=8cm,goc A=90 do .Ve AH vuong goc voi BC .tinh AH

Bai 1: Cho tam giac ABC nhon, duong cao BD, CE
a) CMR: tam giac ABD dong dang voi tam giac ACE
b) CMR: goc BED + goc BCD = 180 do
c) Cho goc BAC = 60 do; dien tich tam giac AED = 90 do . Tinh tam giac ABC

tam giac ABC co goc A=90 do ve ra ngoai tam giac ABC cac tam giac deu ABD va ACE, BE cat CD tai I. CMR:

a)BE=CD

b)tam giac BDE can

c)goc EIC=60 do va IA la P/G cua goc DIE

cho tam giac aBC vuong tai A co goc B=30 do, AB=6cm,Tia phan giac goc C cat AB tai D.Tinh AB va BD

cau 1 cho tam giac can abc co ab=ac=17 va bc=30 ve ra ngoai tam giac abc tam giac bcd voi cbd=90 do va cd song song voi ab tinh do dai bd

cau 2 cho tam giac abc co goc b =70 do goc c =40 do cac duong cao bd va ce cat nhau tai h goi i la trung diem cua ah m la giao cua tia phan giac goc eid voi bc tinh goc imd