1, the distance from the point on the bisector of the angle is equal to both sides of the angle.

2. The distance between the points on the vertical line of the line segment and the points at both ends of the line segment is equal.

3. The distance from each point on the circle to the center of the circle is equal to the radius of the circle.

4. The locus of the point with equal distance to two parallel lines is parallel to these two lines, and the distance to them is equal.

5. The locus of a point whose distance to a straight line is equal to a fixed value is two straight lines parallel to this Austrian straight line and whose distance is equal to a fixed value.