17. Let the universal set $I=\{(x, y) \mid x, y \in R\}$, and the set $A=\{(x, y) \mid x \cos \theta+y \sin \theta-2=0, x, y, \theta \in R\}$. Then on the $X O Y$ plane, the points corresponding to the elements of the set $\bar{A}$ form a figure with an area of $\qquad$.
17. $4 \pi$