#include #include constexpr double pi = acos(-1); int main() { double r, R, theta; scanf("%lf%lf", &r, &R); theta = 2 * pi - 2 * asin(r / R); printf("%.20lf\n", theta); printf("%.20lf\n", pi * ((R + r) * (R + r) - (R - r) * (R - r)) * (theta / (2 * pi)) + pi * r * r); }