Order of the people does not affect the total number of ways. Thus, we use combinations.
Total combinations: 20C5 = 15,504 ways.
C=pid
Since d=9m and pi=3.142, C=3.142*9m=28.278
Rounded to 1 decimal point =28.3
1.825 rounded to the nearest hundredth is 1.83 because the number after 2 is 5
Let the measure of the unknown angle is x °
Supplementary angles sum up to 180°. So the supplementary angle of x° will be (180 - x)°
According to the given data, measure of x is 40° less than 3 times the measure of its supplementary angle (180 - x). So we can set up the equation for this scenario as:

So the degree measure of the required angle is 125°.