http://www.google.com/search?q=gaia&oq=gaia&aqs=chrome..69i57.2890j0j7&sourceid=chrome&es_sm=119&ie=UTF-8#q=pangea
Read several of these and look carefully at the images.
what are 3 examples that make scientists believe that the continents once fit together?
2 answers
The similarities of the outlines of the continents
The similarities of some of the life forms of the continents
http://en.wikipedia.org/wiki/Continental_drift
The similarities of some of the life forms of the continents
http://en.wikipedia.org/wiki/Continental_drift