Before going to the program first let us see what is Slope and Midpoint of a Line and how to calculate it?

Slope of a Line:

The Slope of a Line is a number that describes both the direction and the steepness of the line.

Midpoint of a Line:

The Midpoint of a Line is the middle point of a line segment. It is equidistant from both endpoints.

To calculate we should know the formulas.

So the formulas are:

## Program code to Calculate Slope and Midpoint of a Line in C:

```#include<stdio.h>
#include<conio.h> void main()
{ float x1,x2,y1,y2,slope,midX,midY; clrscr(); printf(" Enter the X Coordinate of Endpoint 1: "); scanf("%f",&x1); printf(" Enter the Y Coordinate of Endpoint 1: "); scanf("%f",&y1); printf(" Enter the X Coordinate of Endpoint 2: "); scanf("%f",&x2); printf(" Enter the Y Coordinate of Endpoint 2: "); scanf("%f",&y2); printf(" The Endpoints of a Line are : (%.2f,%.2f) and (%.2f,%.2f)",x1,y1,x2,y2); slope=(y2-y1)/(x2-x1); midX=(x1+x2)/2; midY=(y1+y2)/2; printf(" Slope : %.2f",slope); printf(" Midpoint : (%.2f,%.2f)",midX,midY); getch();
}
```

## Explanation:

• First the computer reads the X and Y Coordinate of the Endpoint 1 from the user and stores it in the “x1” and “y1” variables respectively using the following lines:
```printf(" Enter the X Coordinate of Endpoint 1: ");
scanf("%f",&x1);
printf(" Enter the Y Coordinate of Endpoint 1: ");
scanf("%f",&y1);
```

Note: %f is used to read the floating-point value.

• Then the computer reads the X and Y Coordinate of the Endpoint 2 from the user and stores it in the “x2” and “y2” variables respectively using the following lines:
```printf(" Enter the X Coordinate of Endpoint 2: ");
scanf("%f",&x2);
printf(" Enter the Y Coordinate of Endpoint 2: ");
scanf("%f",&y2);
```
• Then using the formulas the Slope and Midpoint of a Line is calculated and stored in the “slope” and “midX”, “midY” variables respectively using the following lines:
```slope=(y2-y1)/(x2-x1); midX=(x1+x2)/2;
midY=(y1+y2)/2;
```
• Finally the Slope and Midpoint of a Line is printed on the screen using the following lines:
```printf(" Slope : %.2f",slope);
printf(" Midpoint : (%.2f,%.2f)",midX,midY);
```

Note: %.2f is used to print the floating-point value with only 2 decimal places.