yen tam di, to con nhieu de lam day ne............
"1, Cho tam giac ABC vuong goc tai A, goc B bang 20 do.AH la duong cao cua tam giac ABC, ve tia phan giac HP cua goc AHB, khi do goc APH bang...?
2, Cho tam giac ABC vuong goc tai A, co goc B = 30 do. AH la duong cao cua tam giac ABC
(H thuoc BC) . HD la tia phan giac cua goc AHC (D thuoc AC). Khi do goc ADH =...........?"
Hai bai toan trong violympic 7 do.