Consider the vectors r1 = (2.39 m) i + (- 5.07 m)j and r2 = (- 3.56 m) i + (0.98 m)j for the next questions. Calculate the magnitude of r1. Calculate the angle of r1. Your angle in degrees should be greater than zero - this means that your final answer should state the angle as measured counterclockwise from the starting point at the x- axis