Các câu hỏi tương tự
Cho 1 duong thang cat 2 duong thang song song,Hay chung minh rang:
a,Cac tia phan giac cua 1 cap goc so le (hoac so le ngoai thi song song voi nhau
b,Cac tia phan giac cua 1 cap goc dong vi thi song song voi nhau.
c,Cac tia phan giac cua 1 cap goc trong cung phia(hoac ngoai cung phia) thi vuong goc voi nhau.
Chung to rang neu hai duong thang song song thi cac tia phan giac cua moi cap goc dong vi song song voi nhau.
|x-1,25|=2,75
Cho tam giac ABC co B=45°,C=75°. Phan giac BAC cat canh BC tai M. Qua M ke dg thang song song voi dg thang AB cat canh AC tai N.
1, tinh so do cac goc BAC va goc AMB
2,tinh so do cac goc cua tam giac AMN
A=1/4/23-5/21-4/23+1,5+1/16/12
Cho tam giac ABC co B=45°,C=75°.phan giac BAC cat canh BC tai M. Qua M ke dg thang song song voi dg thang AB cat canh AC tai N
1, tinh so do goc BAC va goc AMB
2, tinh so do cac goc cua tam giac AMN
Ve hinh dum nha
ghi gt kl cua cac dinh li sau , ve hinh
a, neu 2 dg thang phan biet // dg thang thu 3 thi chung // voi nhau
b, neu 2 tia phan giac cua 2 goc ke bu thi vuong foc voi nhau
can gap ngay bay gio
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
bai 1. cho doan thang zz' cat 2 duong thang song song xx' va yy' thu tu tai A vaB . ve tia At la tia phan giac cua xAz' va tia BM la tia phan giac cua zBy'. CMR : At // BM
bai 2 cho tam giac ABC tren nua mat phang bo BC chua diem A ve tia Cx song song voi AB. Ve tia Cy la tia phan giac cua ACx. ve tia Az la tia phan giac cua BAC. CMR Cy // Az
cho tam giac abc phan gic goc b cat ac o d. qua d ke duong thang cat ab o e sao cho edb =ebd qua e ke duong thang song song voi bd cat ac o f chung minh ed song song voi dc; ef la tia phan giac cua aeb
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