Area of a square from diagonal length in C++

A diagonal of a polygon is the line joining two vertices that are not adjacent to each other.

The formula for calculating the area of a square with diagonal length is a² = d² / 2, where a and d are the side and diagonal length of the square, respectively. The visual representation of the derivation of the formula is given below:

Here are some example scenarios to calculate the area of a square from the diagonal length using the above formula:

Scenario 1

Input: d = 10
Output: 50

Explanation:
Using the formula: area = d2 / 2
= 102 / 2
= 100 / 2 = 50
=> area = 50

Scenario 2

Input: d = 15
Output: 112.5

Explanation:
Using the formula: area = d2 / 2
= 152 / 2
= 225 / 2 = 112.5
=> area = 112.5

Program to Find Area of Square From Diagonal

In this example, we have used the formula (a² = d²/2) to find the area of the square if the diagonal is given:

#include <iostream>
#include <math.h>
using namespace std;

int main()
{
   double d = 10;
   double area = (d * d) / 2.0;
   cout << "Area of square of diagonal " << d << " is " << area;
   return 0;
}

The output of the above code is as follows:

Area of square of diagonal 10 is 50