# Polar to Rectangular conversion in C++

In this tutorial, we are going to learn Polar to Rectangular conversion in C++. Here we will learn about the rectangular form, polar form, and Polar to Rectangular conversion. After that, we will see the C++ program for the same. Let us see how to represent z=a+ib in polar form:-

As, shown in the figure:
r ²
= a ² + b ² (Pythagoras theorem)

By using the basic trigonometry:

=> cosθ=a/r and sinθ=b/r

=> a=rcosθ  and b=rsinθ

Substitute the values of a and b in z=a+ib, we get
z=a+bi=rcosθ+(rsinθ)i=r(cosθ+isinθ)
This is called as polar form.

## Conversion of polar form to rectangular form in C++

To convert polar form to rectangular form i.e.
r(cosθ+isinθ) to a+ib
we have to calculate the value of a and b:-
a = r cos θ

b = r sin θ

and substitute these values in a+ib to get the rectangular form.

#### C++ program

So, here is the C++ implementation of the above conversion:-

#include<bits/stdc++.h>
using namespace std;

/*===============================================
FUNCTION FOR CONVERSION FROM POLAR TO RECTANGULAR
================================================*/
void convert_to_rect(int r, int angle)
{
int a,b;
//Calculating values of a and b
a=r*cos(angle);
b=r*sin(angle);
//Displaying rectangular form
cout<<"Rectangular form is: "<<a<<" + i("<<b<<")"<<endl;

}

/*======================================
MAIN FUNCTION
=======================================*/
int main()
{
int r,angle;
r=5;
angle=10;
//Displaying Polar form
cout<<"Polar form is: "<<r<<"*(cos("<<angle<<")+isin("
<<angle<<"))"<<endl;
//Passing r and angle to convert_to_rect function
convert_to_rect(r,angle);
return 0;
}


Output:-

Polar form is: 5*(cos(10)+isin(10))
Rectangular form is: -4 + i(-2)