Write a void type function called circle() to calculate the circumference and area of a circle.
The radius and two variables are passed to the function, which therefore has three parameters:
Given a circle with radius r:
Area = pi * r * r and circumference = 2 * pi * r where p = 3.1415926536
Test the function circle() by outputting a table containing the radius, the circumference, and the area for the radii 0.5, 1.0, 1.5, . . ., 10.0.
// circle.cpp // Defines and calls the function circle(). #include <iostream> #include <iomanip> #include <string> using namespace std; // Prototype of circle(): void circle( const double& rad, double& um, double& fl); const double startRadius = 0.5, // Start, end and endRadius = 10.0, // step width of step = 0.5; // the table int main() //from www.jav a2 s .com { double rad, circuit, plane; cout << setw(10) << "Radius" << setw(20) << "Circumference" << setw(20) << "Area\n" << endl; cout << fixed; // Floating point presentation for( rad = startRadius; rad < endRadius + step/2; rad += step) { circle( rad, circuit, plane); cout << setprecision(1) << setw(8) << rad << setprecision(5) << setw(22) << circuit << setw(20) << plane <<endl; } return 0; } // Function circle(): Compute circumference and area. void circle( const double& r, double& u, double& f) { const double pi = 3.1415926536; u = 2 * pi * r; f = pi * r * r; }