Oasis B is 8.0 km due east of oasis A. Starting from oasis A, a camel walks20 km in a direction 15.0° south of east and then walks 31 km due north. If it is to then walk directly to B, (a) how far and (b) in what direction (in the range of (-180°, 180°)) must it walk (relative to the positive direction of the x axis within the range (-180°, 180°])?