C 1. Cho dg tran (O) during king AB lay diem C thuss during Irm Bị bổ sung (231) (6) sao cho AC (BC. Ve tip tuyon bos voi do tron (o). Gara Ciki -do Mg vg goc BC + a Clm CA 1 CB va PC la tip Augen ang (0) tai I. Tia UI cat ties toyers Bedayo. 고 b) Ke' CHI ABCH EAB) CHEIAD taik. Goi Eta ...