Forces of 18 pounds and 9 pounds act on each other with an angle of 161. Round the magnitude to 4 decimal places and the angles to one decimal place. The magnitude of the resultant force 9.93237 pounds. The resultant force has an angle of -20.0713493 The resultant force has an angle of 181.0713493 Xwith the 18 pound force. Xwith the 9 pound force. Be careful on this one. One of the angles could be obtuse. Also, it is best to calculate each angle separatel and check by seeing if they add to 161.