Area of a circle

Question

We are going to write a program that will calculate the area of ​​a circle.
The area enclosed by a circle of radius r is πr², where π (pi) is the constant ratio of the circumference of any circle to its diameter, and r is the radius.
The given program declares a constant pi variable with a value of 3.14.
Complete the program to take the radius as input, then calculate and output the area of the circle.

Sample Input
5

Sample Output
78.5

Answer 1

Hi Alexander, can you show us your attempts at solving the problem? It would give us better context to understand where you are stuck.

Answer 2

https://www.sololearn.com/Content-Creation-Guidelines/

https://www.sololearn.com/discuss/1316935/?ref=app

Answer 3

Hi hatsy,

My solution is below

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SoloLearn
{
class Program
{
static void Main(string[] args)
{
const double pi = 3.14;
double[] radius = {5,6.4,10};
double area;
int i =0;
double t = Convert.ToDouble(radius[i++]);

switch(t)
{
case 5:
area = pi
* (t * t);
Console.WriteLine(area);
break;
case 6.4:
area = pi
* (t * t);
Console.WriteLine(area);
break;
case 10:
area = pi
* (t * t);
Console.WriteLine(area);

Answer 4

Read the task description carefully:
"Complete the program to take the radius as input"