Question

Write a program that prompts the user to enter the sides and their length of a regular polygon and display its area.

****Using c++

Answer 1

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
int sides;
float length;

cout<<"Enter the Number Sides of Regular Polygon : ";
cin>>sides;
if(sides < 0) {
       cout << "The shape cannot have minus number sides.";
       return 0;
   }
   cout<<"Enter Length of Each Sides : ";
   cin>>length;
   if(length < 0) {
       cout << "The shape cannot have minus length of sides.";
       return 0;
   }

   float perimeter=sides*length; // calculate perimeter = sides*length of each side

   float deg_to_rad = 3.1415926536/180; // degree to radian

   float apothem=(length/tan((180/sides)*deg_to_rad))/2; // calculate apothem = length / 2*tan(180/side)

   cout<<endl<<"Area of Regular Polygon With "<<sides<<" sides is : "<<0.5*perimeter*apothem<<" sq. unit.";

   return 0;
}
Output :