Theorem 5.8b: The area of an {n/k} star inscribed in a circle of radius r is

n[r2sin(180/n)cos(180/n) - s2sin(180(k-1)/n)cos(180(k-1)/n)]

proof: If we look at the following figure

we see that the star can be divided into n blue regions which are obtained by taking the orange isosceles triangle away from the isosceles triangle which are obtained by combining the orange and blue triangle. A simple application of Corollary 5.1b yields the result.

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