Maybe can somebody optimize this?

Question

const double pi = 3.14;
double radius = Convert.ToDouble(Console.ReadLine());
double x = radius * radius;
double y = x * pi;
Console.WriteLine(y);

Answer 1

Your code is fine. If you wantedto shorten it a little, you could write something like
Console.WriteLine(radius*radius*pi);
(then you don't need x and y)