Let’s call, more conventional, the small and big radius r and R, where R>=r. Then the volume and area are:
V== 2 Pi^2 r^2 R A== 2 Pi^2 r R
You specify V= 90 Pi^2. Then A can be written as a function of only one variable, e.g. r:
A = =V/r R == V/(2 Pi^2 r^2)
Therefore, the largest value of A of infinity is reached for r->0.
The smallest value of A is reached if r == R:
rmin = V^(1/3)/(2^(1/3) (Pi)^(2/3))
In your case for V= 90 Pi^2