C Program to Identify a Quadrilateral

Table of Contents

The program to identify a quadrilateral read inputs – length of sides and angles made by the quadrilateral shape and prints the shape name as output.

We compiled the program using Dev-C++ compiler installed on a windows 7 64-bit system. You may try another standard C compiler, but make sure to modify the code according to your compiler specifications.

Problem Definition

A quadrilateral is a polygon shape that has 4 sides and corners that make 4 angles. The sum of those angles must be equal to . There are many types of quadrilateral shapes, you will find a brief description of each shape below.

Square

A square has 4 equal sides and 4 right angles at each corner.

Rectangle

A rectangle has 4 sides with parallel sides are of the same length and 4 corners are right angles. The rectangle has a longer side and a shorter side.

Rhombus

A rhombus is like a square or diamond with 4 equal sides, but none of the corners is a right angle.

Parallelogram

Any quadrilateral that has a pair of parallel sides is a parallelogram. There are shapes which demonstrate properties of parallelogram – square, rectangle, and a rhombus are special case of a parallelogram.

Trapezoid

If a quadrilateral contains at least one pair of parallel lines then it is called a trapezoid.

Kite

A kite is a quadrilateral that has a pair of adjacent sides of equal length and the angle where these two pair meet are equal.

Flowchart

Program Code

#include <stdio.h>
#include <stdlib.h>
int main()
{
        float a, b, c, d, sum = 0.0;
        float angle[3], arr[3], len, tmp; int i;
        int flag, square, rectangle, rhombus, para, trap;
        flag = square = rectangle = rhombus = trap = 0;
        para = 0;
        printf("Enter length of all sides of the Quadrilateral:");
        scanf("%f", & arr[0]);
        scanf("%f", & arr[1]);
        scanf("%f", & arr[2]);
        scanf("%f", & arr[3]);
        len = arr[0];
        printf("Enter Angles of all Corners of the Quadrilateral:");
        for (i = 0; i < 4; i++)
       {
                scanf("%f", & angle[i]);
        if (angle[i] == 90)
       {
               flag++;
       }
}

/* 360 degree check */
        for (i = 0; i < 4; i++)
        {
                sum = sum + angle[i];
        }
                if (sum == 360)
                {
                        printf("sum of angle is 360 n");
                }
                else
                {
                        printf("Sum of Angles is not 360:n");
                        abort();
                }

/* Identify Square */
          for (i = 0; i < 4; i++)
         {
                  if (arr[i] == len)
                 {
                           square++;

                 if (square == 4 && flag == 4)
                {
                          for (i = 0; i < 30; i++)
                          printf("_"); printf("\n\n");
                          printf("It is a Square:\n\n");
                          for (i = 0; i < 30; i++)
                          printf("_"); printf("\n\n");
                }
         }
}

/* Identify rectangle */
if (arr[0] == arr[2] && arr[1] == arr[3] && arr[0] != arr[3] && flag == 4)
{
                for (i = 0; i < 30; i++)
                printf("_"); printf("\n\n");
                printf("It is a Rectangle:\n\n");
                for (i = 0; i < 30; i++)
                printf("_"); printf("\n\n");
}

/* identify parallelogram */
          for (i = 0; i < 4; i++)
         {
                 if (angle[i] == 90)
                 {
                         para++;
                 }
         }
                 if (arr[0] == arr[2] || arr[1] == arr[3])
                {
                     if (para < 4)
                    {
                         for (i = 0; i < 30; i++)
                         printf("_"); printf("\n\n");
                         printf("It is a Parallelogram :\n\n");
                         for (i = 0; i < 30; i++)
                         printf("_"); printf("\n\n");
                    }
                }

/* Identify Kites */
if (arr[0] == arr[1] || arr[2] == arr[3])
{
       if (para < 3 && angle[0] == angle[2] && angle[1] == angle[4])
       {
                if (arr[0] != arr[2])
                 for (i = 0; i < 30; i++)
                 printf("_"); printf("\n\n");
                 printf("It is a Kite :\n\n");
                 for (i = 0; i < 30; i++)
                 printf("_"); printf("\n\n");
       }
}

/* Identify rhombus */
for (i = 0; i < 4; i++)
{
         if (arr[i] == len)
        {
                rhombus++;
                if (rhombus == 4 && angle[i] != 90)
                {
                         for (i = 0; i < 30; i++)
                         printf("_"); printf("\n\n");
                         printf("It is a Rhombus:\n\n");
                         for (i = 0; i < 30; i++)
                         printf("_"); printf("\n\n");
                }
         }
}

/* Identify trapezoid */
for (i = 0; i < 4; i++)
{
        len = arr[i];
        tmp = angle[i];
        for (i = 0; i < 4; i++)
       {
                if (arr[i + 1] != len && angle[i] != tmp)
                {
                        trap++;
               }
        }
}

if (trap == 3)
{
                for (i = 0; i < 30; i++)
                printf("_"); printf("\n\n");
                printf("It is a Trapezoid!\n");
                for (i = 0; i < 30; i++)
                printf("_"); printf("\n\n");
}
system("PAUSE");
return 0;
}

Output

Enter length of all sides of the Quadrilateral:20
20
20
20
Enter Angles of all Corners of the Quadrilateral:90
90
90
90
sum of angle is 360
________________________________
It is a Square:
________________________________

Enter length of all sides of the Quadrilateral:12
12
12
12
Enter Angles of all Corners of the Quadrilateral:60
120
60
120
sum of angle is 360
____________________________
It is a Parallelogram :
____________________________
____________________________
It is a Rhombus:
____________________________