How do you show slideshows on a TV?

Air Play

Export them to the desktop. This makes a QuickTime movie of it. From that you need to connect your mac to the TV, or burn to disk or in someother way make the movie available to it. How you do this really depends on the TV and the Mac you have, and the ports available.

Please don't type in block caps. They are harder to read, and on the forum it looks like you're shouting at everyone.