Question 13
A square is drawn on a plane. Mary chooses a point P on this plane but keeps its position secret. You may draw any straight line on the plane and Mary will tell you whether P lies on one side or on the other side of the line, or on the line itself. The answer is given to you immediately after each line has been drawn. Regardless of the position of the point Mary chooses, what is the minimum number of lines you must draw to find out whether P lies inside or outside the square or on the sides of the square? Explain your answer.