analytic geometry - Can a circle have a negative radius? - Mathematics Stack Exchange

I am working on a problem that asks if a given sphere intersects the zx-plane. The equation of the sphere is $(x-2)^2+(y+6)^2+(z-4)^2=5^2$ Can someone please explain to me how the sphere does not

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Initially in school, we're taught that distances can't be negative, but is it possible to create a circle with a negative radius? - Quora

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