One of my review questions is the following: "A box is pulled along the floor by a horizontal force of 35 N. Another force acts concurrently on the box with a force of 25 N at an angle of 40 degrees above the horizontal in the same direction as the first force. What is the sum of the two vectors?" I got the magnitude of the vector to be 56 N by finding the square root of the horizontal and vertical components respectively squared. However, how does one find the angle. I know I need to calculate the inverse tangent of something - but what?