In the following, find the vector representing the area of a surface. The magnitude of the vector equals the magnitude of the area; the direction is perpendicular to the surface. Since there are two perpendicular directions, we pick one by giving an orientation for the surface.

(a) The area vector $\vec{A_1}$ for the rectangle with vertices $(0,0,0)$, $(-2,0,0)$, $(-2,1,0)$, and $(0,1,0)$, oriented so that it faces downward.
$\vec{A_1} =$

(b) The area vector $\vec{A_2}$ for a circle of radius 2 in the $yz$-plane, facing in the direction of the positive $x$-axis.
$\vec{A_2} =$