# Write a C Program To Find Area Of Circumference | Programs

Another program – to find out the area of circumference of circle. As we already cover area of circle here. You ca check out the program below, if you do have any doubts do let me know. I can help you out related to any programming questions.

Using Standard Method

1)The formula for circumference of circle is c=(2*22*r)/7.

2)The radius value will store into the variable “r”.

3)By substituting the “r ” value into the formula we will get circumference value,that value will store into the variable “c”.

output:

Using Function

1)Here we using the function float area(int r) to calculate  the area of circumference circle.

2)We will call the function using area(r),here we are passing the value of “r”.

3)The called function “area(int r)” will calculate the area of circumference

and returns the value,the return value will assigned to the variable “a”.

output:

Using Pointers

1)We are calling the function by passing addresses as arguments in area(&r,&c).

2)The function void area(float *r,float *a) will calculate the area of circumference which is having pointer arguments.

3)The calculated value will be store into the variable a.

output:

Using Macros

1)line 2 represents area(r) is symbolic name to the expression (2*22*r)/7

2)area(r)replaced with that expression given at #define.

output: