#include<iostream>
#include<cmath>
using namespace std;

int main(){

	typedef struct{
		double x, y;
	}_point;

	double a, b, s, t, r_p3, r_p2, eps;
	_point p1, p2, p3, p;
	
	eps = 10e-6;

  while(cin >> p1.x >> p1.y >> p2.x >> p2.y >> p3.x >> p3.y >> p.x >> p.y){
		p2.x -= p1.x;
		p2.y -= p1.y;
		p3.x -= p1.x;
		p3.y -= p1.y;
		p.x -= p1.x;
		p.y -= p1.y;
		r_p2 = sqrt(p2.x * p2.x + p2.y * p2.y);
		r_p3 = sqrt(p3.x * p3.x + p3.y * p3.y);
		if(p2.x > eps){
			s = p.y - p.x * p2.y / p2.x;
			t = p3.y - p3.x * p2.y / p2.x;
			a = (s / t);
			b = (p.x - a * p3.x) / p2.x;
		}
		else {
			a = p.x / p3.x;
			b = (p.y - a * p3.y) / p2.y;
		}

		if(a > 0.0 && b > 0.0 && a + b < 1.0) cout << "YES" << endl;
		else cout << "NO" << endl;
  }

  return 0;
}