tong cac so do goc cua HT va TG la 360
tu giac MNPQ co M+N+P+Q=360
159+N+Q-360
N+Q=201
Mà N=2Q
Nen 2Q+Q=201
3Q=201
Q=67
MN//PQ NEN M+Q=180
SUY RA M=113
Tam giac ABC co AB=AC
goc A=100do M thuoc tam giac ABC
goc MBC=10 do goc MCB=20 do
Tim goc AMB?
Mong cac ban tu ve hinh va giai nhanh hio mih con lam
Cho goc tu AOB trong do ve cac tia OC,OD theo thu tu vuong goc voi OA,OA
a, So sanh cac goc AOD va BOC
b, Goi OM la tia phan giac cua goc COD . Xet xem OM co phai la tia phan giac cua goc AOB ko?
do dai ba canh cua tam giac ABC co do dai banh 4;12;x biet x la mot so tu nhien . tim x ( cho biet moi canh cua tam giac nho hon tong hai canh va lon hon hieu cua chung)
CHO GOC NHON XOY TREN OY LAY DIOEM M TU M KE MN VUONG GOC VOI OX TAI N TU N KE NP VUONG GOC OY TAI P TU P KE PQ VUONG GOC TU Q KE OE VUONG GOC OY TRONG HINH VE CO BAO NHIEU CAP SONG SONG VI SAO BIET OQE = 40 DO TINH SO DO GOC NHON TRU XO
Cho tam giac ABC co goc A =90 do ,AB=AC .Goi K la trung diem cua BC a,cmr:tam giac AKB= tam giac AKC va AK vuong goc BC b,tu C ve duong thang vuong goc voiBC cat AB tai M goi N la trung diem cua CM cmr CM//AK va KN =0.5BM
X3m hinh 46 voi hinh 1 , tam giac da cho la mot tam giac vuong, co mot goc nhon la x va goc nhon kia la 50 auy ra.x+50 =90 hay x = 40
Cho biet so do gocy,z,t ,m trong moi hinh ve o hinh 46
cho tam giac can ABC (AB=AC) co goc A khong phai goc vuong . Tu A ke mot tia vuong goc voi AB cat duong thang BC o D. TInh hieu giua cac so do cua hai goc C va D cua tam giac ACD
cho tam giac abc, goc A tu, tren canh BC lay diem M, N sao cho BN=BA, CM=CA
a, so sanh goc AMC va ANB
b, so sanh canh AM va AN
c, biet goc ABC =40 do, goc ACB =30 do , tinh so do 3 goc cua tam giac AMN
cho tam giac abc can tai c va goc c = 100 do bd la phan giac cua goc b tu a ke ax tao voi ab mot goc 30 do tia ax cat bd tai m cat bc tai e bk la phan giac abd bk cat ax tai n tinh acm so sanh mn va ce