picture source: http://www.google.com/imgres?imgurl=&imgrefurl=http%3A%2F%2Fsport.maths.org%2Fcontent%2Fsports-equipment&h=0&w=0&tbnid=LkNaG91WHti21M&zoom=1&tbnh=234&tbnw=215&docid=d7NNPncpka_dCM&tbm=isch&client=safari&ei=qtFlU7qOKbK0sQS15IHQCw&ved=0CAsQsCUoAw
linear version
if this version cannot be opened, here is a link to a page that will take you straight to my linear version
if this version cannot be opened, here is a link to a page that will take you straight to my linear version