例
#include <bits/stdc++.h>
using namespace std;
//寻找外接圆的半径
float findRadiusOfcircumcircle(float n, float a) {
if (n < 0 || a < 0)
return -1;
float radius = a / sqrt(2 - (2 * cos(360 / n)));
return radius;
}
int main() {
float n = 5, a = 6;
cout << findRadiusOfcircumcircle(n, a) << endl;
return 0;
}输出结果
3.02487