complimentary means that when the measures of both angles are added together they equal 90 degrees. To get the answer you subtract 48 from 90 and get 42. Then you subtract 10 from 42 because it is added in the parentheses. Then you divide 32 by 2 and you get your answer which is 16.
To find this answer, just divide 360 by 5 to find out how many times his heart beats in one minute instead of 5. Doing this will give you a final answer of 72 bpm.
