The coordinates of the top points are , . If a lattice point is inside the square ,
then the lattice point is called a "good point". The number of good points inside the square is .
The coordinates of the top points are , . If a lattice point is inside the square ,
then the lattice point is called a "good point". The number of good points inside the square is .
4. 197.
As shown in Figure 6, through point , draw
perpendicular to sides
at ,
. It is easy to see that
we know , which means
Simplifying, we get .
Thus, or , which means
Therefore, is a point on the diagonal or on the diagonal .
Similarly, when is a point on the diagonal or on the diagonal , it satisfies
Thus, is a good point if and only if is an internal lattice point on the diagonal or the diagonal .
It is easy to see that there are 99 good points on the diagonal , and there are also 99 good points on the diagonal . It is also easy to see that the intersection point of the diagonals and is also a good point. Therefore, the number of good points that satisfy the condition is .