Question

点C是AB的中点,点D是线段AB的六等分点,且CD=6,求AC的长

Answer 1

已知,AC = BC = (1/2)AB ,BD = (1/6)AB ,

可得：CD = BC-BD = (1/3)AB ,即有：AB = 3CD ,

所以,AC = (1/2)AB = (3/2)CD = 9 .