



 
Hi Scott, I think I understand. Here is my diagram I am going to develop a general expression showing the quantities you sent in red. In the diagram f is the width of the opening (f = 96 inches) and h is the rise of the arc (h = 18 inches). C is the centre of the circle that subtends the arc and r is the radius of the circle. Since triangle ABC is a right triangle Pythagoras Theorem gives (f/2)^{2} + (r  h)^{2} = r^{2}. Solving for the radius r gives
Again, since triangle ABC is a right triangle sin(angle BCA) = (f/2)/r so (angle BCA) = sin^{1}(f/(2r) and
Now suppose there are to be n window units (n = 5). Each window unit then subtends an angle of measure (angle DCA)/5. Call the measure of this angle t^{o} (t^{o} = 82.2/5 = 16.4^{o}). In the diagram below the line segment QP represents one window unit and S is the midpoint of QP. Let the width of the window be w units then PS = w/2. Since the measure of the angle QCP is t^{o} the measure of the angle SCP is t^{o}/2. Hence
I hope this helps,  


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