Standard Circle Equation

#math #SAT #geometry

Equation

$(x - h)^{2} + (y - k)^{2} = r^{2}$

Key Information Extraction from equation:

Component	Standard Form	From Your Equation: $(x + 4)^{2} + (y - 19)^{2} = 121$
Center $(h, k)$	$(h, k)$	Since $(x + 4)^{2}$ is $(x - (- 4))^{2}$ , the center is $(- 4, 19)$
Radius Squared (r²)	$r^{2}$	$r^{2} = 121$
Radius (r)	$r$	$r = \sqrt{121} = 11$