In 2006, a group of art museums collaborated to form the West Texas Triangle to promote their collections. This region is formed by the cities of Odessa, Albany, and San Angelo. The approximate coordinates of each location, respectively, are 31.9°N102.3°W,32.7°N99.3°W and 31.4°N100.5°W . Write a coordinate proof to prove that the West Texas Triangle is approximately isosceles.