(1)
EC = AC - AE = (5/9 - 1/2) AD = AD / 18 = 2cm
所以,AD = 18 * 2 = 36cm
(2)
AB:BE = AB:(AE - AB) = (2/9)*AD:(1/2 - 2/9)*AD = 2/9 :5/18 = 4:5
(1)
EC = AC - AE = (5/9 - 1/2) AD = AD / 18 = 2cm
所以,AD = 18 * 2 = 36cm
(2)
AB:BE = AB:(AE - AB) = (2/9)*AD:(1/2 - 2/9)*AD = 2/9 :5/18 = 4:5