... cita quan (AB) Vrn AB = -4 -+ 3 (1 . ;- 3) = 25 3, Di~m ngang mong (BB') BB' = AB = 6 25 4 ' 4, Ha goi (AC) AC = ~g + 5 = 52 ,5 Tu cae ditm xac dinh ke ... A,A6 ~ 1 ,5 98 B9 B, 0 - l I Vbl4 + chiet(3) Ar, 8 A, "\ A- 5 lA, 1\ :; ::if "/ Y 13" 8, B, Vm/4+CEls B, ~B, Vml1 0-1 B5 VmI 10+1 - C 5 C, C C' ... Vm/4+CEJ\ m • V mliO-1 B5 B2 3, 5 B, B3 B VrnI 10+1 - C 5 C4 C C +2 C6 C, C' 2 ·C, C C Xs X4 X, X X, X3 X V6I2+2 VO/ 2-2 Hinh 7.2 - Mf/i quem hf giii'a...