PROCEDURE:- 1.enter an integer value 2. set a=0,b=1,c=a+b,flag=0 3.repeat steps 4 ,5 until c is less than or equal to n 4.if n and c are same print that n is Fibonacci number 5.else set a=b,b=c, c=a+b 6 if n is not equal to c it is not Fibonacci number CODE:- #include<stdio.h> void main() { int n, a=0,b=1 ,c,flag=0; printf(“enter a number”); scanf(“%d”,&n); do { c=a+b; if(n= = c) { flag=1; break; } a=b; b=c; }while(c<=n); if(flag = = 1) printf(“%d is Fibonacci number”,n); else printf(“%d is not Fibonacci number”,n); } Input:- enter a number 8 Output:- 8 is Fibonacci number