Quandaries
and Queries 

I need to fabricate a 10 section, 4" pipe circle with an inside diameter of 40". I would like to know what angles would apply and how to find them, thank
you 

Hi Gil, I drew a diagram of what I think you are describing.
AB is one of the 10 lengths of pipe and C is the center of the region. Since there are 10 lengths of pipe the angle BAC is ^{360}/_{10} = 36^{o}. The sum of the angles in a triangle is 180^{o} and hence angle ABC is ^{(180  36)}/_{2} = 72^{o}. Thus the angle at the end of each length of pipe is 72^{o}. Penny 

