Crossing a is the symmetrical point of the river bank A', connecting A'b, crossing p, then p is the drinking place.

A line segment is a limited part (including two endpoints) between two points on a straight line, which is different from a straight line and a ray.

Line segments are represented by letters A and B or lowercase letters representing their two endpoints. Sometimes these letters also represent the length of the line segment, which is recorded as line segment AB or line segment BA and line segment A, where A and B represent the two endpoints of the line segment.

Application of line segment:

1. links link the two in different places, as do other indicative supplements.

2. Separation separates two areas in the same place, as do other areas such as depth of field and equipotential line.

3. Delete examples: When writing an article, in order to keep the creative process, cross out inappropriate sentences with lines, as do other stops in the route.