tren mat phang cho 40 diem trong do co 30 diem thang hang hoi ve duoc tat ca bao nhieu tam giac tu 40 diem da cho?????????????

Cho hinh vuong ABCD . Tren nua mat phang chua diem B la duong thang AD ve tia AM(M thuoc CD) sao cho MAD=20. Cung tren nua mat phang nay ve tia AN ( N thuoc BC )sao choNAD=65.Tu B ke BH vuong AN( H thuoc AN) va tren tia doi cua HB lay p sao cho HB=HP c|m ; a) 3 diem N;P; M thang hang. b)Tinh cac goc cua tam giac AMN.

ho tam giac abc . Tren nua mat phang co bo la duong thang AC chua diem B ve tia AD//BC .Tren nua mat phang doi voi nua tren ve tia AE//BC.Tren nua mat phang doi voi nua tren ve tia AE//BC a cmr 3 diem A,D,E thang hang ,b Tinh tong cac goc trong cua tam giac?

Trong mat phang chon 6 diem phan biet, trong do khong co 3 diem nao thang hang. voi 3 diem bat ki trong 6 diem do luon co 2 diem ma khoang cach nho hon 673. CMR trong 6 diem da cho luon tim duoc 3 diem la 3 dinh cua mot tam giac co chu vi nho hoc 2019

Cho 20 diem trong do khong co 3 diem nao cung nam tren 1 duong thang hoi co the ve duoc bao nhieu hinh tam giac 3 trong 20 diem da cho lam dinh

cho 21  dien khong co 3 diem nao thang hang ve duoc bao nhieu tam giac co 3 dinh la 3 tong cac diem da cho

Cho tam giac ABC vuong can tai A, D la mot diem bat ki tren canh AB. Tren nua mp bo AB co chua diem C, ve tia?

mat phang bo AB co chua diem C, ve tia Bx de goc ABx=135 do. Duong thang vuong goc vs Dc ve tu D cat tia Bx tai E. Chung minh tam giac DEC can

giups mk

cho tam giac ABC co goc a nhon M la trung diem cua BC tren tia doi cua tia MA lay diem D sao cho MA=MD chung minh BAM=CDM chung minh AC=AD tren nua mat phang Bo AB ko chua C ve tia Ax vuong goc AB tren nua mat phang bo AC ko chua B ve tia Ay vuong goc AC tren tia Ax lay Diem P sao cho AP=AB tren tia Ay lay diem Q sao cho AQ=AC chung minh tam giac ABQ= tam giac APC goi giao diem cua DA va PQ la K chung minh AK vuong goc PQ