Cho tam giac ABC.Tu trung diem D cua canh BC,Ke duong vuong goc voi phan giac cua goc A cat AB tai M,AC tai N

a)Chung minh :BM=CN

b)Biet AB=C,AC=B .TINH AM,BM(gia su B>C) theo a va b

CAC BAN VE HINH HO MINH LUON NHA 

BAI 1: 

13 PHAN 3 : X PHAN 4 = 6: 0.3

BAI 2 CHO TAM GIAC ABC VUONG TAI A BIET GOC B = 40DO

a; TINH C

b; GOI I LA TRUNG DIEM AC. TREN TIA BI LAY D  SAO CHO ID=IB. CM TAM GIAC ABI=TAM GIAC CDI

c; CM AC VUONG GOC CD

cho tam giac ABC co AB=AC; goc BAC=108^0.Goi O la trung diem cua BC; phan giac goc B cat AC tai E. Cmr:AO=1/2 BE.

Cho tam giac ABC co goc BAC =90 do lay diem M thuoc cach BC sao cho goc MAC =20 do

   a, tinh goc MAB 

   b, Trong goc MAB ve tia Ax cat BC tai N sao cho goc NAB = 50 do .Chung to AM la tia phan giac cua goc NAC

Cho tam giac ABC co goc BAC=50\(^o\).O la giao diem cua 2 tia phan giac cua goc B va goc C.

a) Tinh goc BOC

b)  Diem O co cach deu 3 canh cua tam giac khomg?Tai sao

c)  Ke tia AD.Tinh goc BAO

CAC BAN KE HINH HO MINH LUON NHE CO GIUP MINH NHA

Tam giac ABC can tai A: goc A =100°. Phan giac cua goc ABC cat Ac o D. Chung minh BC= BD+AD.

Vẽ hình nữa nhé

cho mnp vuong tai m.Ke mn vuong goc nk,tia phan giac cua goc pmk cat np tai i.Chung minh NM=NI

cho tam giac abc co goc a vuong , ab= 30cm , ac=45cm.M la 1 diem tren canh ab sao cho am=20cm. Tu M ke duong thang song song voi canh bc cat canh ac tai diem n.Hoi:  a/ tinh S abc, b/ tinh S anm

cho hinh tam giac abc vuong goc a . biet ab=10 vm va ac=14cm. tren bc lay trung diem m trem ac lay dinh d sao cho dc =1/3 ac. noi b voi d, noi a voi m cat nhau tai i tinh dien tich hinh tu giac imcd

    GIUP MINH NHA ! CAM ON NHIEU NHIEU