Since the polygon is a square, the diagonal is [tex]\sqrt{2}[/tex] times the side of the square. The diagonal is 14 yards, so the side of the square is 7[tex]\sqrt{2}[/tex] yards. Since the area of a square is it's side squared, the area is (7[tex]\sqrt{2}[/tex][tex])^{2}[/tex], which is 98 square yards.
