Question 1120973
Find the area of a regular octagon inscribed in a circle with radius r
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For any regular polygon:
{{{Area = n*r^2*tan(180/n)}}} --- n = # of sides, r = radius
= {{{r^2*tan(22.5)}}}
= ~ {{{0.414*r^2}}}
= {{{(sqrt(2)-1)*r^2}}}
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Hint:  we don't need hints.