+1 vote

That's a really great idea if you want to compare three programming languages with the same example. If you want to get the area of the circle using C programming, PHP programming, and C# programming, you should understand the area of a circle formula. The mathematics formula for areal of circle - A = **π** r^{2 }

**π - Pai **

**The value of π= 3.14 **

**Radius - r **

**Square of radius - r ^{2}**

The area of circle can be written as pai*r*r in C, PHP, and C# programming.

C programming is known as the computer programming language. This is the base of all programming languages. If you want to learn any programming language,

you should understand the C language first .

You can find out the area of the circle in C language by creating variables and multiplication.

#include<stdio.h>

#include<math.h>

main()

{

float r=2.0;

float pai=3.14;

float a;

a = pai*r*r;

printf("Area of circle = %.2f\n", a);

}

Execute the above C language example and change the radius of the circle.

Let's find out the area of the circle in PHP .

<?php

$pai=3.14;

$r=2.0 ;

$a=$pai*$r*$r;

echo($a);

?>

In PHP, variables are declared with the dollar $ sign.

C# programming is another programming language based on C and C++ concepts. You can find out the area of a circle using C# language.

public class areaOfCircle{

public static void Main(){

// Your code here!

double pai ,a,r;

pai=3.14;

r=2.0;

a=pai*r*r;

System.Console.WriteLine(a);

}

}

0 votes

Thanks for the question. The solution is very easy. You should understand the basic things to find out the area of the circle using C, PHP, and C# programming languages.

Area of the circle = **π** r^{2 }

The value of the **π** = 3.14

r^{2= }r*r;

You need to create three variables .

Follow the best solution reference and change according to your need -

PHP: Add two input box values and sum in the third box

Follow for C# programming

Mathematics operations in C# programming

Area of the circle in C language -

#include<stdio.h>

#include<math.h>

main()

{

float rad=6,9;

float p=3.14;

float area;

area = p*rad*rad;

printf("Area of the circle = %.2f\n", area);

}