tan∠EAN=BE:AB= 1/3

Let the side length of a square be a, BE=a/3 and CE=BC-BE=2a/3.

DC+CE=5a/3= 10

a=6，BE=a/3=2

Let AN be x, thEN en be x and BN be 6-X.

，RT△BEN，BE？ +BN？ =EN？

(6-X)？ +2? =X？

x？ - 12X+40=X？

X= 10/3，

AN=EN= 10/3，BE=8/3，

s△AND = 1/2×an×AD = 1/2× 10/3×6 = 10

(2)sin∠ENB = BE/EN = 2:( 10/3)= 3/5