Write a program that reads the radius of a circle (as a double value) and computes and prints the diameter, the circumference and the area. Use the value 3.14159 for ?.

Question

What will be an ideal response?

Answer 1

```
// Calculate the diameter, circumference and area of a cirle.
#include
using namespace std;

int main()
{
double radius; // input radius
double pi = 3.14159; // value for pi
// get radius value
cout << "Enter the radius: ";
cin >> radius;

// compute and display diameter
cout << "The diameter is " << radius * 2.0;

// compute and display circumference
cout << "\nThe circumference is " << 2.0 * pi * radius;

// compute and display area
cout << "\nThe area is " << pi * radius * radius << endl;
} // end main
```