#include "stdafx.h"
#include <iostream>
#include <math.h>

using namespace std;

void main() {
    setlocale(LC_ALL, "Russian");

    double circle_y = 3.0;
    double circle_x = -7.0;
    double circle_r = 3.0;
    double triangle_v1_x = 0.0;
    double triangle_v1_y = 0.0;
    double triangle_v2_x = -5.0;
    double triangle_v2_y = 0.0;
    double triangle_v3_x = 0.0;
    double triangle_v3_y = 6.0;
    double point_x;
    double point_y;
    double s,s1,s2,s3;

    cout<<"Введите X: ";
    cin>>point_x;
    cout<<endl;

    cout<<"Введите Y: ";
    cin>>point_y;
    cout<<endl;

    s = 0.5*fabs((triangle_v1_x - triangle_v3_x)*(triangle_v2_y - triangle_v3_y) - (triangle_v2_x - triangle_v3_x)*(triangle_v1_y - triangle_v3_y));
    s1 = 0.5*fabs((point_x - triangle_v3_x)*(triangle_v2_y - triangle_v3_y) - (triangle_v2_x - triangle_v3_x)*(point_y - triangle_v3_y));
    s2 = 0.5*fabs((triangle_v1_x - triangle_v3_x)*(point_y - triangle_v3_y) - (point_x - triangle_v3_x)*(triangle_v1_y - triangle_v3_y));
    s3 = 0.5*fabs((triangle_v1_x - point_x)*(triangle_v2_y - point_y) - (triangle_v2_x - point_x)*(triangle_v1_y - point_y));

    if(s == (s1+s2+s3) || (pow((point_y - circle_y), 2.0) + pow((point_x - circle_x), 2.0)) <= pow(circle_r, 2.0))cout<<"Принадлежит"<<endl;else cout<<"Не принадлежит"<<endl;

    system("PAUSE");
}