Cho biet tu diem A thuoc tia phan giac cua goc xoy co mu nha! ve duong thang song song voi Ox cat Oy tai B va ve duong thang song song voi Oy tai C a)chung minh BOA=AOC ,b) chung minh AO la tia phan giac cua BAC

Cho truoc diem a va duong thang d di qua diem a ve 2018 duong thang phan biet . goi x la so duong thang vuong goc voi d, y la so duong thang khong vuong goc void trong 2018 duong thang da cho..

Tim gia tri nguyen lon nhat cua x, y

Tim gia tri nguyen nho nhat cua x,y

Qua diem A o ngoai duong thang a co:

A. Vo so duong thang song song vs a

B. 1 va chi 1 dg thang song song vs a

C. Co it nhat 1 dg thang song song vs a

D. Hai dg thang song song vs a

Ve duong thang a, tu hai dem A,B nam ngoai duong thang a , dung AC;BD  vuong goc voi a (C ,D Thuoc a) Ve duong thang d la duong thang trung truc cua CD cat AB  tai N

Cho tam giac ABC, co AC<AB, M la trung diem BC, ve phan giac AD. Tu M ve duong thang vuong goc voi AD tai H, duong thang nay cat tia AC tai F, cat AB tai E. Chung minh rang:

a) Δ AFE can

b) Ve duong thang Bx//EF, cat AC tai K. Chung minh rang: KF=BE

c) Chung minh rang: \(\frac{AB+AC}{2}\)

Cho tam giac ABC, co AC<AB, M la trung diem BC, ve phan giac AD. Tu M ve duong thang vuong goc voi AD tai H, duong thang nay cat tia AC tai F, cat AB tai E. Chung minh rang:

a) Δ AFE can

b) Ve duong thang Bx//EF, cat AC tai K. Chung minh rang: KF=BE

c) Chung minh rang: AE= \(\dfrac{AB+AC}{2}\)

mk can gap nha (ai giai ki va lm dung mk cho 3 tick)

Cho tam giac ABC co duong phan giac AD. Duong thang di qua diem A va vuong goc voi AD cat BC tai K. Chung minh AK la phan giac cua goc ngoai tai dinh A cua tam giac ABC

cho duong thang xy, cac diem B va C nam tren xy, diem A nam ngoai xy. Hãy neu cach ve duong thang di qua A va song song voi BC.

Viet han cach ve ra ho minh nha !!!! ^_^

tam giac ABC co tia phan giac cua goc B cat AC o D qua A ke duong thang song song voi BD duong thang nay cat duong thang BC o E hay chung to rang goc BAE=goc BEA

CO AI GIAI NHANH HO MINH VOI