Question

如图,已知△ABC,延长BC到点D,使CD=BC,取AB中点F,连接FD交AC于点E, (1)求AE/AC的值 (2)若AB=a,FB=EC，求AC

完整

Answer 1

1)连接FC和AD 三角形EFC 和 三角形 AED 相似
AE/EC = AD/FC = 2/1
所以 AE/AC = 2/3
2)AB = a => EC = a/2 => AC = 1.5 a