Rectangle ABCD is drawn on the Cartesian plane (each grid square is 1 unit). What is its perimeter?

Two perpendicular axes — horizontal $(x$-axis) and vertical $(y$-axis) — meet at the **origin** (0, 0). Together they divide the plane into four **quadrants**:

- **I**: $x>0,y$ > 0 (top right)
- **II**: $x<0,y$ > 0 (top left)
- **III**: $x<0,y$ < 0 (bottom left)
- **IV**: $x>0,y$ < 0 (bottom right)

Points ON the axes don't belong to any quadrant. (a, 0) sits on the $x$-axis; (0, b) sits on the $y$-axis.