- C Programming Examples
- C Programming Examples
- C Print Hello World
- C Get Input from User
- C Print Integer
- C Add Two Numbers
- C Add Subtract Multiply Divide
- C Add n Numbers
- C Area Perimeter of Square
- C Area Perimeter of Rectangle
- C Area Circum of Circle
- C Fahrenheit to Celsius
- C Celsius to Fahrenheit
- C Inches to Centimeters
- C Kilogram to Gram
- C Reverse a Number
- C Swap Two Numbers
- C Interchange Numbers
- C Print ASCII Value
- C Print Fibonacci Series
- C Check Palindrome or Not
- C Check Armstrong or Not
- C Find Armstrong Numbers
- C Find nCr and nPr
- C Find Profit Loss
- C Sum of their Square
- C First & Last Digit Sum
- C Sum of All Digit
- C Product of All Digit
- C Print Total Digit in Number
- C Check Perfect Number
- C Find Basic Gross Salary
- C Round Number to Integer
- C Print Series upto n Term
- C Find Factors of Number
- C if-else & Loop Programs
- C Check Even or Odd
- C Check Prime or Not
- C Check Alphabet or Not
- C Check Vowel or Not
- C Check Leap Year or Not
- C Is Reverse Equal Original
- C Make Calculator
- C Add Digits of Number
- Count Positive Negative Zero
- C Largest of Two Numbers
- C Largest of Three Numbers
- C Smallest of Two Numbers
- C Smallest of Three Numbers
- C Find Factorial of Number
- C Find LCM & HCF
- C Find LCM of n Numbers
- C Find HCF of n Numbers
- C Find Arithmetic Mean
- C Find Average, Percentage
- C Find Student Grade
- C Print Table of Number
- C Print Prime Numbers
- C Find Discount Purchase
- C Calculate Parcel Charge
- C Calculate Wage of Labor
- C Print Phone Bill
- C Conversion programs
- C Decimal to Binary
- C Decimal to Octal
- C Decimal to Hexadecimal
- C Binary to Decimal
- C Binary to Octal
- C Binary to Hexadecimal
- C Octal to Decimal
- C Octal to Binary
- C Octal to Hexadecimal
- C Hexadecimal to Decimal
- C Hexadecimal to Binary
- C Hexadecimal to Octal
- C Pattern Programs
- C Pattern Printing Programs
- C Print Diamond Pattern
- C Print Floyd's Triangle
- C Print Pascal's Triangle
- C Array Programs
- C 1D Array Programs
- C Linear Search
- C Binary Search
- C Largest Element in Array
- C Smallest Element in Array
- C Second Largest/Smallest
- C Count Even Odd
- C Array Element at Even
- C Array Element at Odd
- C Print Even Array Elements
- C Print Odd Array Elements
- C Sum/Product of Even/Odd
- C Reverse an Array
- C Insert Element in Array
- C Delete Element from Array
- C Merge Two Arrays
- C Bubble Sort
- C Selection Sort
- C Insertion Sort
- C Print Common Elements
- C 2D Array Programs
- C Add Two Matrices
- C Subtract Two Matrices
- C Transpose a Matrix
- C Multiply Two Matrices
- C Sum All Matrix Elements
- C Largest Element in Matrix
- C Print Row Column Total
- C 3D Array Programs
- C String Programs
- C Print String
- C Find Length of String
- C Compare Two String
- C Copy a String
- C Concatenate String
- C Reverse a String
- C Count Vowels Consonants
- C Replace Vowel in String
- C Delete Vowels from String
- C Delete Word from String
- C Frequency of Character
- C Count Word in String
- C Remove Spaces from String
- C Sort a String
- C Sort String in Alphabetical
- C Sort Words in Ascending
- C Sort Words in Descending
- C Uppercase to Lowercase
- C Lowercase to Uppercase
- C Swap Two Strings
- C Check Anagram or Not
- C Check Palindrome String
- C Print Number in Words
- C Print Successive Character
- C Character without Space
- C Remove Extra Spaces
- C File Programs
- C Read a File
- C Write Content to File
- C Read & Display File
- C Copy a File
- C Merge Two Files
- C Reverse File
- C Count All Character in File
- C List Files in Directory
- C Encrypt & Decrypt a File
- C Delete a File
- C Misc Programs
- Generate Random Numbers
- C Print Date Time
- C Print Message with Time
- C Get IP Address
- C Print Smiling face
- C Pass Array to Function
- Add Two Numbers using Pointer
- C Address of Variable
- C Shutdown Computer
- C Programming Tutorial
- C Tutorial
- C Programming Library
- C Standard Library
- C Programming Test
- C Programming Test
- Give Online Test
- All Test List
C Program to Calculate Area and Circumference of Circle
In this article, you will learn and get code about calculating area and circumference of a circle.
To calculate area or circumference of any circle in C programming, you have to ask from user to enter the radius of circle say r. Using this radius, to find area, use 3.14*r*r. And to find circumference, use 2*3.14*r. Here 3.14 is the value of π (Pi)
List of programs, available here in this article:
- Find Area of Circle
- Find Area of Circle using Function
- Find Circumference of Circle
- Find Circumference of Circle using Function
Calculate Area of Circle in C
As area of any circle can be calculated using the formula πr2. Here r represents radius of circle, and the value of π (Pi) is equal to 3.14. So the formula can be written as 3.14r2 or 3.14*r*r. Let's take a look at the program:
#include<stdio.h> #include<conio.h> int main() { float rad, area; printf("Enter Radius Value of Circle: "); scanf("%f", &rad); area = 3.14*rad*rad; printf("\nArea = %0.2f", area); getch(); return 0; }
This program was written under Code::Blocks IDE. Here is the first snapshot of sample run:
Now supply any number as radius value of circle say 5 and press ENTER key to see the output as shown in the second snapshot of sample run:
The format specifier, %0.2f is used to print the value of area upto only two decimal place.
Calculate Area of Circle using Function in C
Let's create another program that does the same job but using function as shown here:
#include<stdio.h> #include<conio.h> float findArea(float); int main() { float rad, area; printf("Enter Radius Value of Circle: "); scanf("%f", &rad); area = findArea(rad); printf("\nArea = %0.2f", area); getch(); return 0; } float findArea(float rad) { return 3.14*rad*rad; }
After compiling and executing the above program, you will get the same output as seen from the first program's output. To learn more about function, refer to Function in C tutorial.
Calculate Circumference of Circle in C
As circumference of a circle can be calculated using the formula 2πr. Here the value of π is 3.14, and r represents radius of circle. Therefore, after putting the value of π, the formula becomes 2*3.14*r. Here is the program to find circumference of circle:
#include<stdio.h> #include<conio.h> int main() { float r, circumf; printf("Enter Radius Value of Circle: "); scanf("%f", &r); circumf = 2*3.14*r; printf("\nCircumference = %0.2f", circumf); getch(); return 0; }
Here is the sample run of above program:
Calculate Circumference of Circle using Function in C
Now let's create another program that does the same job as of previous program, but this time using function.
#include<stdio.h> #include<conio.h> float findCircumf(float); int main() { float r, circumf; printf("Enter Radius Value of Circle: "); scanf("%f", &r); circumf = findCircumf(r); printf("\nCircumference = %0.2f", circumf); getch(); return 0; } float findCircumf(float r) { return 2*3.14*r; }
This program produce the same output as seen from previous program's output.
Same Program in Other Languages
- C++ Calculate Area and Circumference
- Java Calculate Area and Circumference
- Python Calculate Area of Circle
- Python Calculate Circumference of Circle
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