EF是AD的中垂线.
∴△EDA为等腰Rt△
∴ED = AE
∵AC = BC = 2
设ED = x
则CE = 2 - x
Rt△EDC中,
CD" + CE" = ED"
⇒2 + (2-x)" = x"
x = 1.5
即AE = 1.5