Line definition

Lines represent an infinite sequence of points to form a continuous line, which can span one, two, or three dimensions. Likewise, there are various criteria to classify the lines, for example, they can be open or closed, or their shape, position or their relationship with other lines can also be considered.

The line is one of the most primitive representations that man has used to graph, write and capture his ideas on some surfaces, and even virtually. It can be said that the history of humanity has been expressed in lines; and currently, all the possibilities that exist to represent them are unimaginable; from simple abstract strokes or stripes, to aesthetic architecture and art designs.

Virtually any graph or drawing needs lines for its representation.

From the physical point of view, the dimension that must be used to express the size of a line is the length, that is, its units are meters, centimeters, inches, millimeters, yards, feet, kilometers, among others.

The lines constitute the basis of any architectural design, since from them, it is possible to project a scale plan that can become a building; Or, an already existing structure can be represented.

It is possible to represent a finite line by limiting its stroke between two points, for example, a curved line connecting points A and B.

Classification: open lines and closed lines

A line may or may not have a defined beginning and end, and depending on this, the stroke that it forms is considered to be open or closed:

Open line: is used to represent an open contour, that is, its two ends never intersect. For example, the letters “L”, “M”, “S” and “C” are strokes made with open lines.

Open lines can be used to draw partial geometric figures, ie open contours.

closed line: generates a closed contour, that is, its start and end coincide at some point. The letters “O”, “B” and “D” are built with closed lines.

The outline of the figure represents a tooth, and is formed by a closed line where its ends meet at some point.

Classification of lines according to their shape

Straight line: These are lines in which all their points are oriented in the same direction, therefore, the line is described in one dimension.

The striping of the road represents a straight line, since it is formed by a succession of points that lead the same direction.

Curved line: are formed by successions of points that change their orientation to two or more directions. These lines occupy two or more dimensions.

The striping of the road represents a curved line, since the succession of points is changing its direction.

Broken line: composed of line segments that are connected by abruptly changing direction and forming angles between them.

The mosaic of the image is formed by broken lines of light and dark tones.

mixed line: consists of strokes that do not follow a specific direction or pattern, and are formed by the combination of curved and straight lines.

The strokes that are made to write form mixed lines, since they combine different types of lines.

Lines according to your position

Vertical line: It is a straight line whose stroke is made from the bottom up or from the top down, forming 90° with the horizon.

Height is a feature that usually represents the length of a vertical line.

Horizontal line: are lines whose construction is traced from left to right or vice versa, and go in the same direction as the horizon. The slope (inclination) of these lines is zero, therefore, they form 0° with the horizon.

The horizontal line owes its name to the fact that its orientation goes in the same direction as the plane of the horizon.

Inclined line: is an oblique line that is neither horizontal nor vertical, so it forms an angle other than 0 or 90 with the horizon.

The see-saw axis shown in the figure represents a sloping line.

Lines according to their relationship with other lines

Parallel lines: for a line to be parallel, it must be compared with another reference line or axis, and in this case, it is said that two or more lines are parallel if the distance at which they are separated is always the same, that is, that never intersect. Parallel lines can be curved or straight.

The steps of the escalator form horizontal lines parallel to each other. Also, the handrails on both sides of the stairs form two parallel lines.

secant linesTwo or more lines are intersecting if they intersect at any point to form angles other than 90.

The orange line is intersecting with the green and purple line, since they intersect in a non-perpendicular way.

Perpendicular lines: These are straight lines that intersect at some point to form right angles.

The white lines that form the striping of the tennis court are perpendicular lines since they form 90° between them.

Following