1) The resultant speed of the river?
2) Which angle is 59.036 degrees? More specifically, is tan(59.036º) = river/downstream or is tan(59.036º) = downstream/river
3) Logically, the rowing is faster than the river. The correct result cannot be greater than 120m. Rough estimate? 120 * 6/10 = 72ish without any trig. It may be exact in this case, but there is not much need to count on that, since you should be learning some trigonometry.