line segment

The length is limited and can be measured.

◆ Two endpoints

Line segment description

Line segment, a general term in technical drawing, refers to a continuous or discontinuous drawing line composed of one or more different line elements, such as a real line segment or a two-point long line segment composed of "long stroke, short interval, point, short interval, point and short interval".

The line segment has the following properties: the line segment between two points is the shortest.

The length between two points is called the distance between them.

Two points on a straight line and the part between them are called line segments.

A line segment is represented by letters or lowercase letters representing its two endpoints. Sometimes these letters also indicate the length of the line segment, which is recorded as line segment AB or line segment BA and line segment A. 。

Between two points, the line segment is the shortest. There is no distance in a straight line. Ray has no distance.

Two points on a straight line and the part between them are called line segments.

① Static definition of angle: A graph composed of two rays with a common point is called an angle. This common point is called the vertex of the angle, and these two rays are called the two sides of the angle.

② Dynamic definition of angle: The graph formed by light rotating from one position to another around its endpoint is called angle. The endpoint of the rotated ray is called the vertex of the angle, the ray at the starting position is called the starting edge of the angle, and the ray at the ending position is called the ending edge of the angle.

(3) Angle symbol:

The size of the angle has nothing to do with the length of the side; The size of the angle depends on the opening degree of both sides of the angle. The bigger the opening, the bigger the angle. Angle can be divided into acute angle, right angle, obtuse angle, right angle and rounded corner.

Acute angle: An angle less than 90 is called acute angle.

Right angle: An angle equal to 90 is called a right angle.

Oblique angle: an angle greater than 90 and less than180 is called obtuse angle.

Boxer: An angle equal to 180 is called a boxer.

Excellent angle: more than180 and less than 360 is called excellent angle.

Fillet: An angle equal to 360 is called a fillet.