To calculate area of a circle by taking radius as input with algorithms, Flowchart and coding.

Algorithm:

Step 1: Start

Step 2: Input value of radius

Step 3: Calculate area ( area = 3.14 * radius * radius )

Step 4: Display value of area

Step 5: Stop.

Flowchart:

Program:

  #include<stdio.h>

  int main()

  {

      int radius;

      float PI = 3.14, area;

      printf("\n Enter radius of circle: ");

      scanf("%d", &radius);

      area = PI * radius * radius;

      printf("\n Area of circle : %f ", area);
  
      return (0);

  }

Output:

Enter radius of circle: 3

Area of circle : 28.260000