Let's start by opening a new document. Draw a rectangle with the Rectangle Tool (M). I chose the size of 415pt by 6pt and filled it with a nice blue. Draw a circle with the Ellipse Tool (L), and make it 27px in diameter. Place the circle in the center of the rectangle. Set the Stroke to 6pt and choose the same blue. Next, go to Object > Path > Outline Stroke.
We need to combine both objects. We can do so by selecting both and then choose the Divide tool in the Pathfinder Palette. Delete all the unnecessary paths, then select the final desired shape, and choose the Add to Shape Area in the Pathfinder Palette.
