• # question_answer If the area of an equilateral triangle inscribed in the ${{x}^{2}}+{{y}^{2}}+10x+12y+c=0$ is $27\sqrt{3}\,sq.$ units then $c$ is equal to: A) $13$ B) $20$ C) $-25$ D) $25$

$r=\sqrt{25+36-c}=\sqrt{36}$ $c=25.$