# C Program to Find the Length of the String

This C program calculates the length of a given string.

## Problem Statement

Write a program that calculates the average of three numbers entered by the user.

The program should perform the following steps:

1. Prompt the user to enter three numbers.
2. Read the three numbers from the user.
3. Calculate the average of the three numbers.
4. Display the calculated average on the screen.

Example:

Enter the first number: 5 Enter the second number: 7 Enter the third number: 3 The average of the three numbers is: 5.0

Requirements:

1. The program should be written in C programming language.
2. The user input and output should be handled through the console.
3. The average should be displayed with one decimal place.
4. The program should handle both integer and floating-point input.

You can use the provided problem statement as a guide to write the code. Remember to include necessary input validation and error handling to ensure the program functions correctly.

## C Program to Find the Length of the String

```#include <stdio.h>

int main() {
double num1, num2, num3;
double average;

printf("Enter the first number: ");
scanf("%lf", &num1);

printf("Enter the second number: ");
scanf("%lf", &num2);

printf("Enter the third number: ");
scanf("%lf", &num3);

average = (num1 + num2 + num3) / 3;

printf("The average of the three numbers is: %.1lf\n", average);

return 0;
}
```

## How it Works

1. The program starts by prompting the user to enter three numbers. This is done using `printf` statements to display messages to the user on the console.
2. The program then uses `scanf` to read the three numbers entered by the user. The numbers are stored in variables for further processing.
3. Next, the program calculates the average of the three numbers. It does this by adding the three numbers together and dividing the sum by 3. The average is stored in a variable.
4. Finally, the program displays the calculated average on the console using a `printf` statement. The average is printed with one decimal place by using the format specifier `%.1f`.

Here’s an example of how the program would execute:

Enter the first number: 5 Enter the second number: 7 Enter the third number: 3 The average of the three numbers is: 5.0

In this example, the user enters the numbers 5, 7, and 3. The program calculates the average as (5 + 7 + 3) / 3 = 5.0 and displays it on the console.

Please note that the program assumes valid input from the user. It doesn’t handle scenarios where the user enters invalid input, such as non-numeric values. Adding input validation and error handling is important to ensure the program behaves as expected in all situations.