Which sets of side lengths represent pythagorean triples? check all that apply.
1, 2, 5
6, 8, 14
8, 15, 17
10, 24, 26
15, 20, 30
28, 45, 53

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.