小学数学题
#include<cstdio>
#include<cmath>
using namespace std;
const double PI = 3.1415926;
int main () {
int t, a, b;
double d, dayuan, xiaoyuan, sanjiao, r, xiaoyuanR, ans;
scanf("%d", &t);
while (t--) {
scanf("%d %d %lf", &a, &b, &d);
r = d / 2;
dayuan = PI * r * r;
xiaoyuanR = sqrt(2*r*r) / 2;
xiaoyuan = PI * xiaoyuanR * xiaoyuanR;
sanjiao = (r * r) / 2;
ans = xiaoyuan / 2 + sanjiao - dayuan/4;
printf("%.8lf\n", ans*4);
}
return 0;
}