Find the area of equilateral triangle inscribed in a circle `x^2+y^2+2gx+2fy+c=0`

Explanation

Given circle `x^2+y^2+2yx+2f+c=0`


Let `o` centre of triangle ABC in equilateral triangle


`o=[-g,-f]` `OA=OB=OC=sqrt(g^2+f^2-c)`


In ` triangle OBM= sin 60^@= (BM)/(OB)`


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