Given that one of the angles of the triangle with sides (5, 7, 8) is 60°, show that one of the angles of the triangle with sides (3, 5, 7) is 120°. I don't really see how these two triangles are related. I think that the first triangle side with 7 is angle 60°, and 7 on the second triangle is also 120°. I have also tried connecting the two triangles together into a quadrilateral, the same integers sharing a side. I'm wondering if I could get a hint of how to solve this. Thank you.