http://i41.tinypic.com/29dbjm0.jpg please help
From what I observed, should be 3 routes. Portland to Tucson; Portland to Las Vegas to Tucson; and Portland to San Diego to Tucson. Calculate the distances for all these 3 routes and determine which is the shortest and the longest. the inequality would be: length of shortest route<= distance between P and T<=length of longest route.
why thank u:)