cho tam giac ABC vuong tai A va cho AB=c BC=a AC =b
tim GTNN cua
M = 8a^2 (1/b^2 +1/c^2) + (b+c)/a +2016
ai giup vs
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
Bai 1 giai tam giac ABC vuong tai A, biet
a/ AB = 6cm, ˆBB^ = 40
b/ AB= 10cm, ˆCC^ = 35
c/BC=32cm, AC = 20cm
d/ AB = 18cm, AC=21cm
Bai 2 Cho △ABC co AB=40cm , AC=58cm , BC=42cm
a/ △ ABC co phai la tam giac vuong hay k ? vi sao ?
b/ Ke duong cao BH cua tam giac . Tinh do dai BH ?
c/ Tinh ti so luong giac cua goc A
Bai 3 : Cho △ABC co AB=5cm , ˆBB^ =60 , ˆAA^ = 45
a/ tinh do dai BC va AC
b/ Tinh dien tich △ABC
Cho tam giac ABC co AB = 6 cm, AC = 4,5cm, BC = 7,5cm
a. Chung minh tam giac ABC vuong tai A. Tinh cac goc B, goc C va duong cao AH cua tam giac.
b. Tim tap hop cac diem M sao cho S(ABC) = S(BMC).
Cac ban giup mk vs nha mk dag can gap a.
Cam on mn nha.😝😝
bai 1:Cho duong tron tam O, day AB. cac tiep tuyen ke tu A,B cat nhau tai C. ke day CD cua duong tron co duong kinh OC(D khac A,B). CD cat cung nho AB cua (O) tai E (E nam giua C va D).Chung minh:
a/goc BED= goc DAE
b/DE^2=DA*BD
bai 2:Cho tam giac ABC deu noi tiep duong tron tam O. M la diem nam tren cung nho AB. chung minh:
a/MB+MA=MA
b/ke MH vuong goc voi BC, MI vuong goc voi AB, MK vuong goc voi AC. chung minh 3 diem H,I,K thang hang
1. Cho tam giac ABC vuong tai A phan giac AH biet CD =68cm, BD =51cm. Tinh BH,HC
2. Cho tam giac ABC vuong tai A duong cao AH biet AB=7,5cm ; AH=6cm.
a) Tinh AC,BC
b) Tinh cos B, cos C
1. cho tam giac ABC M;N lan luot la trung diem cua CA ,CB ;I la diem bat ki tren MN (I khac M;N ) C/M trong 3 tam giac ICB;ICA;IAB; co 1 tam giac ma dien tich cua no bang tong cac dien tich cua 2 tam giac con lai
2. cho tam giac ABC tren cac canh AB;AC;CA keo dai ve phia B;C;A lay B1;C1;A1 sao cho BB1=b;CC1=c; AA1=a c/m a/AC+b/ AB+c/BC>HOAC =3
cho tam giac ABC, duoang cao AK .goi 3diem D,E,F lan luot la trung diem cua AB,AC,BC
a) BDEF la hinh gi ? vi sao
b) chung minh ADEF la hinh thang can
c) goi H la truc tam cua tam giac ABC.M,N,P theo thu tu la trung diem cua HA ,HB,HC.chung minh cac doan thang MF ,NE,PD bang nhau va cat nhau tai trung diem moi doan
BAI 2 cho tam giac ABC co AB=6,AC=8,BC=10.goi AM la trung tuyen cua tam giac
a)tinh AM
b)ke MD vuong goc voi AB,ME vuong goc voi AC.tu giac ADME co dang dac biet nao ?
c)DECB co dang dac biet nao