Quartz 4

C++ Hypotenuse calculator practice program 📐

3 min read

Notes

This video demonstrates a practice project in C++ to calculate the hypotenuse of a right triangle using the Pythagorean theorem. The formula to calculate the hypotenuse *C* of a right triangle is:

Where:

  • *a a*nd *b* are the lengths of the two legs of the triangle, and
  • *C* is the length of the hypotenuse.

Let’s break down the steps involved in writing this program:

Step-by-Step Explanation:

  1. Declare the Variables:

    • We first declare three variables of type double to store the values of the two sides a and b of the triangle, and the hypotenuse C :

      double a, b, c;
  2. Include the Necessary Header:

    • Since the program will involve mathematical operations like squaring and finding square roots, we need to include the <cmath> library:

      #include <cmath>
  3. Accept User Input for Sides aa and bb:

    • We use std::cin to accept the side lengths a and b from the user. We use std::cout to prompt the user to enter the values.

      std::cout << "Enter side a: ";
std::cin >> a;
std::cout << "Enter side b: ";
std::cin >> b;
  4. Perform the Calculation:

    • The calculation involves squaring the two sides ( a^2 and b^2 ), summing them, and then taking the square root of the result. This can be done using the pow() function to square the numbers, and sqrt() to compute the square root:

      c = std::sqrt(std::pow(a, 2) + std::pow(b, 2));
  5. Display the Result:

    • After the calculation, the result (the value of c ) is displayed using std::cout:

      std::cout << "The hypotenuse is: " << c << std::endl;
  6. Shortening the Code (Alternative):

    • The formula can be written in a more compact form, eliminating the need for separate lines to square the sides:

      c = std::sqrt(a * a + b * b);

    • This line does the same thing: squaring a and b and adding them before applying the sqrt() function.

Complete Code Example:

#include <iostream>
#include <cmath>
 
int main() {
    double a, b, c;
 
    // Accept user input for sides a and b
    std::cout << "Enter side a: ";
    std::cin >> a;
    std::cout << "Enter side b: ";
    std::cin >> b;
 
    // Calculate the hypotenuse
    c = std::sqrt(std::pow(a, 2) + std::pow(b, 2));
 
    // Display the result
    std::cout << "The hypotenuse is: " << c << std::endl;
 
    return 0;
}

Explanation of Key Functions:

  1. std::pow(x, y):
    • This function is used to raise a number to a specific power. For example, std::pow(a, 2) computes a^2 , or a squared.
  2. std::sqrt(x):
    • The sqrt() function computes the square root of a number. In this case, it computes the square root of the sum of a^2 and b^2 , which gives us the hypotenuse C .

Example Run:

Let’s assume the following inputs and outputs:

Input:

  • a=3
  • b=4

The program will compute:

Output:

The hypotenuse is: 5

If you change the input to:

  • a=4
  • b=5

The program will compute:

Output:

The hypotenuse is: 6.4

Summary:

  • This program teaches you how to accept user input, perform basic mathematical operations, and display the result.
  • It uses standard C++ functions from the <cmath> library like pow() for exponentiation and sqrt() for square roots.
  • The project helps reinforce your understanding of type conversion, mathematical functions, and user input in C++.

If you want a copy of this code, the author mentions they will post it in the comments section for reference.

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