Question

Shelby and Martin take turns flying remote controlled airplanes. Beginning at the top of a flagpole, Shelby's airplane flew 18.1 feet due south, turned and flew 9.5 feet due east, and then turned again and flew directly back to the top of the flagpole. Also beginning at the top of the flagpole, Martin's airplane flew 9.5 feet due north, turned and flew due west, and then turned again and flew directly back to the top of the flagpole.

Which of the following would prove that Martin flew in a congruent triangular pattern as Shelby?