How can I watch torrents I have downloaded on my TV?

I have downloaded some torrents to my MacBook Pro. I would like to watch them on my parents TV, but it is not a digital one. It's one of the old types with an RCA three pronged plug. The guy at the Apple store was not very helpful. Can I just buy a cord with an USB and RCA and use the TV like a monitor? Is there some other way of doing this?