This is program is based on a simple mathematical concept. The degree is converted to radian value or radian is converted to degrees for computing trigonometric identities.

In this program we used two formulas for following

- Radian to Degree conversion
- Degree to Radian conversion

This program is intended for beginners of C++ programming language and we used Dev C++ 4.9.9.2 compiler to compile and run this program. However, you can use any other standard C++ compiler to compile and execute the program.

To help you learn, go through each section given below,

- Problem definition
- Flowchart
- Program code
- Output

### Problem Definition

In this C++ program, the user makes one of the two choices – perform radian to degree conversion or degree to radian conversion. Since, this program is based simple math, we used formulas given below.

**Converting from radian to degree**

The formula to convert radians to degree is

Degree = radian * 180/π

**Converting from degrees to radians**

radian = degree * π/180

When a user start the program, the C++ program does following.

- Ask to choose a conversion method
- Ask input values based on the conversion chosen by the user.
- Use formula for conversion
- Print the output value.

See the flowchart section for logical flow of the program.

### Flowchart

### Program Code

```
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
float radian, degree, pi;
int choice;
pi = 3.14;
// Menu
cout << "1.Radian to Degree" << endl;
cout << "2.Degree to Raidan" << endl;
cout << "\n\n";
cout << "Enter Your Choice:”;
cin >> choice;
// Switch starts here
switch (choice)
{
Case 1:
cout << "Enter Radian Value to Convert: ";
cin >> radian;
cout << "\n\n";
degree = radian * 180/pi;
cout << "The Degree Value for" << " " << radian << " " << "radian is" << " " << degree << " " << "degree"<< " " << endl;
break;
Case 2:
cout << "Enter Degree Value to Convert:";
cin >> degree;
cout << "\n\n";
radian = degree * pi/180;
cout << "The Radian Value for" << " " << degree << " " << "degree is" << " " << radian << "radian" << " " << endl;
break;
default:
cout << "Wrong Value! Try again later" << endl;
}
system ("pause");
return EXIT_SUCCESS;
}
```

**Output**

The output of the above program is given below. When a user enters the radian measure(0.785) the corresponding degree value is computed and displayed on the console.