A phone line runs east along a field of 1.6 miles and then north along the edge of the same field for 2.5 miles. If the phone line cost 3500 per mile to install, how much could have been saved if the phone line had been installed diagonally across the field?
the diagonal is (1.6+2.5) - √(1.6^2 + 2.5^2) = 1.13 miles shorter
so now you can figure the savings