Question

Which of the following is the equation of a circle with a radius of 10 cm and center at (–3, 6)?

Answer 1

The equation of the circle:

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

(h, k) - center

r - radius

We have:

$r=10\\(-3,\ 6)\to h=-3,\ k=6$

Substitute:

$(x-(-3))^2+(y-6)^2=10^2\\\\(x+3)^2+(y-6)^2=100$