Answer
$ c=3$
Work Step by Step
The volume of ellipsoid
$\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}+\dfrac{z^2}{c^2}=1$
is given as
$V=\dfrac{4}{3} \pi a \space b \space c $
Now plug in the variables,
$\dfrac{4 \times 1 \times 2 \times c \space \times \pi}{3}=8\pi $
Now, solve for $ c $.
Therefore, $ c=3$
