1. The problem statement, all variables and given/known data Look at the image.All the O's are of equal length.O1=O2=O3 etc.Angles are subtended from two ends of An O to point P.As you see,O1's angle is larger than O2 ant )2's angle is larger then O3 and so on. As you Go down the O's(i.e. O1,O2,O3 etc),the angle subtented by the O's Decrease and that too with a decreasing rate. What would be the angle of nth O. See the image Clearly please.. 2. Relevant equations a+d(n-1) ar^(n-1) 3. The attempt at a solution As the angles decrease with decreased rate,The Formulas are not usable. What should I do?Angles are not even inversely proportional to O's.