Help!

Question

I am trying to learn C#. I’m new to coding, so I’m still figuring out how it all works. The first project asks you to build a code that will read the input (radius of a circle) and then formulate the area of a circle. I cannot for the life of me figure out what is wrong with this code. Please, someone help!!

https://code.sololearn.com/cK6d9HI2bGF0/?ref=app

Answer 1

// This will help you

radius = Convert.ToDouble(Console.ReadLine());
Console.Write(pi*radius*radius);

Answer 2

double int radius; // this is error because variable may be double type or int type but not both types..

string x = radius; // radius still uninitialzed so error
int y = pi; // double to int, loss of data, error

radius = Console.ReadLine(); // this will read a line of string. So input is in string format. Convert to needed destination type..

You just need a double type input.
And formula is pi * radius * radius for output..

// for reading input of double type value..
double radius = Convert.ToDouble( Console.ReadLine() );

Output :
Console.Write( pi * radius * radius);

Answer 3

https://code.sololearn.com/chtUt5UN667m/?ref=app
I corrected the code so that it works now I tried to mostly Just delete unnecresary parts and change Something a little.
Some Points there:
-When you want a numeric input like here should you directly declare it in int with convert (See code)
-Next when you make a calculation with double make the variable for the result also double.