The output is different from the correct answer

[Mehereema]

#include <stdio.h>
int main () {
int radius;
printf("radius is ");
scanf("%d", &radius);
float pi=22/7;
int r=radius*radius;
printf("area of circle is %f", pi*r);
return 0;
}
Why is the output 147? The answer should be 154 as I put the radius value 7.

 

[ratwolf]

#include <stdio.h>
int main () {
int radius;
printf("radius is ");
scanf("%d", &radius);
float pi=22/7;
int r=radius*radius;
printf("area of circle is %f", pi*r);
return 0;
}
Why is the output 147? The answer should be 154 as I put the radius value 7.

#include <stdio.h>
int main () {
int radius;
printf("radius is ");
scanf("%d", &radius);
float pi=22/7;
int r=radius*radius;
printf("area of circle is %f", pi*r);
return 0;
}
Why is the output 147? The answer should be 154 as I put the radius value 7.

22 / 7 is integer division in C because both 22 and 7 are integers. Integer division discards the decimal part and gives you just the integer result.

22 / 7 = 3   // not 3.14

Make at least one operand a float to ensure floating-point division:

#include <stdio.h>
int main () {
    int radius;
    printf("radius is ");
    scanf("%d", &radius);
    float pi = 22.0 / 7; // or use 3.14159
    int r = radius * radius;
    printf("area of circle is %f", pi * r);
    return 0;
}

 

[Mehereema]

22 / 7 is integer division in C because both 22 and 7 are integers. Integer division discards the decimal part and gives you just the integer result.

22 / 7 = 3   // not 3.14

Make at least one operand a float to ensure floating-point division:

#include <stdio.h>
int main () {
    int radius;
    printf("radius is ");
    scanf("%d", &radius);
    float pi = 22.0 / 7; // or use 3.14159
    int r = radius * radius;
    printf("area of circle is %f", pi * r);
    return 0;
}

Thank you so much. I'm totally new, and it helped me a lot. You made it so easy