Issue with Area of a Circle Test

Question

I solved 5 of the 6 Test Inputs, but it errors on Test Input #2 = 6.4
Can anyone help me understand why? The error is very confusing.

Here is my code:

const double pi = 3.14;
double radius =

Convert.ToInt32(Console.ReadLine());
double area = (radius*radius)*pi;

Console.WriteLine(area);

Answer 1

6.4 is a float value. Don't convert input to integer.