16
81

is shaded.

Let x and y be the distances shown. Then the shaded area is 8y + x. But there are a number of similar triangles and from one pair x/8 = y/1 i.e. x = 8y. So,
shaded area
total area
 = 8y + x
9(x + y)
 = 8y + 8y
9 ×9y
 = 16
81