tinh cac goc cua tam giac can biet duong phan giac ung voi canh day bang 1/2 duong phan giac ung voi canh ben
Cho tam giac ABC. Mot duong thang song song voi BC cat cac canh AB, AC theo thu tu o D va E. Goi G la mot diem thuoc canh BC. Tinh dien tich tu giac ADGE biet dien tich tam giac ABC bang 16cm, dien tich tam giac ADE bang 9 cm
Giai ho minh de nay voi cac p:cho tam giac ABC can tai A,duong cao AH,AB=8cm,BC=10cm
a,tinh BH,AH
b,goi BK va CI la cac duong phan giac cua tam giac ABC,chung minh rang tu giac BIKC la hinh thang can
cho tam giac abc vuong tai a,co ab=9,bc=15
a) tinh do dai canh ac va so ssanh cac goc cua tam giac abc
b) tren tia doi cua tia ab lay diem d sao cho a la trung diem cua doan thang bd.chung minh tam giac bcd can
c) goi k la trung diem cua canh bc. duong thang dk cat canh ac tai m.tinh do dai doan thang mc
d) duong trung truc cua canh ac cat duong thang dc tai q.chung minh ba diemb,m.q thẳng hàng
BAI 1 : cho hinh thang ABCD khong co goc vuong biet tong do dai 2 canh day AB va CD thi bang do dai canh ben AD cmr cac duong phan gaic trong goc A vs goc D di qua trung diem E cua BC
Bai 2 : cho hinh thang ABCD co AB//CD cmr neu CD = AD + BC thi cac duong phan giac cua cac goc A va B cat nhau tai 1 diem thuoc canh day CD
Lam giup mink vs mink dang gap lam . THANKS
Cho hinh thang can ABCD. Day nho AB bang canh ben BC va duong cheo AC vuong goc oi canh ben AD.
a) Tinh cac goc cua hinh thang can
b)Chung minh rangg trong hnh thang can do day lon gap doi day nho
cho hinh thang can abcd (ab song song cd và ab<cd)canh ben dai 1 cm goc tao boi day lon va canh ben co so do bang 60 do cd=2,7 cm tinh do dai ab
cho hinh thang ABCD co goc A=100 do , goc C=70 do va canh day AB bang canh ben AD
chung minh tam giac DBC can
Bai 1;Cho tu giac ABCD (AB//CD) co cac tia phan giac cua cac goc C va D gap nhau tai I thuoc canh ben BC
CMR;AD bang tong cua hai day
Bai 2;cho tam giac ABC vuong tai A,BC=2cm.Ve tam giac ACE vuong tai E (E khac phia doi voi AC ).
CMR;AECB la hinh thang vuong.Tinh cac goc va cac canh cua no