1, the straight line in the first picture is separated from the circle, and there are two points with the same distance;

2. The straight line in the second picture is tangent to the circle and has two points with the same distance;

3. The straight line in the third picture bisects the radius of the circle vertically, and there are three points with equal distance;

4. The straight line in the fourth picture intersects with the circle, and there are four points with equal distance.

The nature of the circle:

1、? In the same circle or in the same circle, if the distance between two central angles, two peripheral angles, two sets of arcs, two chords and one of the two chords is equal, the corresponding other groups are equal.

2. In the same circle or equal circle, the circumferential angle of an equal arc is equal to half of the central angle it faces (the circumferential angle and the central angle are on the same side of the chord).

3. Triangle has definite circumscribed circle and inscribed circle. The center of the circumscribed circle is the intersection of the perpendicular lines of each side of the triangle, and the distances to the three vertices of the triangle are equal.