Why are roof lines different in New England and the Southwest?

Why are roof lines different in New England and the Southwest?

In at least 250 words, give a full and complete answer to the question. I would like you to find out about the material and describe the answer in your own words. Most of these topics require some research. Don’t forget that you must give attribution to your source. Be sure to cut and paste the URL of the site from which you got the information.