# Foci of an Ellipse

Foci is a point used to define the conic section. F and G seperately are called "focus", both togeather are called "foci".

### Foci of an Ellipse formula

\(\large{ c^2 = a^2 - b^2 }\)

Where:

\(\large{ c }\) = length center to focus

\(\large{ a }\) = length semi-major axis

\(\large{ b }\) = length semi-minor axis

\(\large{ F }\) and \(\large{ G }\) = focus