360 degrees (degrees of a circle) divided by 18 (the equal parts) equals 20 degrees, so each part is 20 degrees. 20 degrees times 5 parts equals 100, so the degrees of the 5 parts is 100.
--6.6,6,-5,3/5,5/8,27/5,5.8
The circumference is 37.7
hope it helps:)