When you put your 2 rounded ends together you get a perfect circle so let's find the circumference around that circle first. [tex]C= \pi d[/tex] which of course gives us a circumference of [tex]140 \pi [/tex]. Now add in 300 + 300 to get 600+140pi, and when you multiply 400 times pi and add in the 600 you get 1039.8, which is your 1040 above.
