C Program To Find Area of Circle

In this article, we are going to write a c program to find area of circle.

We will make this program in the following way -:

• C Program To Find Area of Circle (Simple Way)
• C Program To Find Area of Circle Using Function
• C Program To Find Area of Circle Using Pointer
• C Program To Find Area of Circle Using Mirco or #define

To make this program, we will use the following concept given below.

• Function in C
• Pointer in C
• Macro in C

If you do not know about these topics well, then you may not understand this program, so you should know about them in detail from the link given above.

Now without wasting time let’s start programming.

C Program To Find Area of Circle (Simple Way)

Algorithm

• Program Start
• Declare Variables
• Input Radius From User
• Calculate the Area of the Circle
• Display Result
• Program End

Program

#include<stdio.h>
void main()
{
float r,aoc;
printf("Enter the radius : ");
scanf("%f",&r);
aoc=3.14*(r*r);

printf("area of circle is : %f",aoc);

}

Output

Enter the radius : 5
area of circle is : 78.500000

C Program To Find Area of Circle Using Function

Algorithm

• Program Start
• Declare Variables
• Input Radius From User
• Calling Function To Calculate Area of Circle
• Calculating Area of Circle
• Display Result
• Program End

Program

#include<stdio.h>
void areaofCircle(float r)
{
 float aoc;

 aoc=3.14*(r*r);

 printf("area of circle is : %f",aoc);

}
void main()
{
float r;
printf("Enter the radius : ");
scanf("%f",&r);

areaofCircle(r);
}

Output

Enter the radius : 7
area of circle is : 153.860001

C Program To Find Area of Circle Using Pointer

Program

#include<stdio.h>
void areaofCircle(float *r, float *aoc)
{
 	*aoc=((3.14)*(*r)*(*r));

}
void main()
{
float r, aoc;
printf("Enter the radius : ");
scanf("%f",&r);

areaofCircle(&r,&aoc);

printf("area of circle is : %f",aoc);

}

Output

Enter the radius : 3
area of circle is : 28.260000

C Program To Find Area of Circle Using Micro or #Define

Program

//C Program To Find Area of Circle Using Micro or #Define

#include<stdio.h>
#define pi 3.14
void areaofCircle(float r)
{
 float aoc;

 aoc=pi*(r*r);

 printf("area of circle is : %f",aoc);

}
void main()
{
float r;
printf("Enter the radius : ");
scanf("%f",&r);

areaofCircle(r);
}

Output

Enter the radius : 10
area of circle is : 314.000000

Read More

• Download C Language Notes Pdf
• C Language Tutorial For Beginners
• C Programming Examples With Output
• 250+ C Programs for Practice PDF Free Download

Conclusion

So friends, in this article, we have written a c program to find area of circle In this ways -:

• C Program To Find Area of Circle (Simple Way)
• C Program To Find Area of Circle Using Function
• C Program To Find Area of Circle Using Pointer
• C Program To Find Area of Circle Using Mirco or #define

If you have difficulty to understand any program or have any doubts or questions, then tell me in the comment below.