For this boot up draw a horizontal line of circles, each circle touching the
ones next to it in line, and the whole line centered centered vertically and
horizontally. The circles should have radius r (a variable
defined in the starter code) and you should draw as many as will fit in the
drawing area.
Writing this method will require using a loop. You will also need to get the computer to do some math for you to figure out how many circles to draw and where they go.