I cannot tell from what you wrote whether the figure is like this:in which case we would subtract m∠ROS = 7ー5'8" from +m∠ROT = 48ー12'16" m∠ROT = 48ー12'16" -m∠ROS = 7ー 5' 8" 覧覧覧覧覧覧覧覧覧覧覧覧 m∠SOT 41ー 7' 8" or whether it's like this: in which case we would add them: m∠ROT = 48ー12'16" +m∠ROS = 7ー 5' 8" 覧覧覧覧覧覧覧覧覧覧覧覧 m∠SOT 56ー17'24" Edwin