



 
Hi Jan, A while ago Stephen developed an expression for the area $A_{RP}$ of a regular polygon with $n$ sides and side length $a$ units. his expression is \[A_{RP} = \frac{a^2 n}{4 \tan\left(\frac{360^o}{2 n}\right)}\] You know that $n = 8$ and $A_{RP} = 1,165$ square feet and hence you can solve for $a.$ I got $a = 15.53$ feet but you should check my calculations. I think you are interested in the width of the octagon. In this response Stephen shows that the width $w$ is related to the side length $a$ by \[a = 0.4142w\] (Stephen uses $x$ where I have used $a.$) I hope this helps,  


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