Equation Of a Straight Line

A straight line with no width can also be thought of as an infinite dimensional figure. It’s a collection of infinite points with the two sides of each point connected. In this we do not get to see any kind of curve. It is generally seen as horizontal, vertical or oblique. If an angle is measured between any two points of a straight line on the plane, then we get 180-degrees. One can see many examples of straight lines in our daily life as well, In which there can be mainly railway tracks, rulers, some parts of the road made of stairs, etc. Through this article, we will learn about the straight line and some equations related to it, which are described below.

What is a Straight Line?

A straight line is an infinitely long line that has nothing to do with a curve. It is constructed between two points on a plane, these ends can be anywhere in infinity. A straight line has no end point, which we can understand by taking the example of railway tracks. It is a straight figure which consists of two points X (a1, b1) and Y (a2, b2) between them, we can extend it to infinity. It is better represented in the figure below, which are as follows;

Types

There are mainly three types of straight lines, which are mainly classified on the basis of alignment. Alignment mainly refers to angles, which are made primarily along the x-axis or y-axis. Here they are described in their context, which are as follows;

Horizontal line- A line drawn horizontally is called a horizontal line, it is mainly drawn parallel to the x-axis and perpendicular to the y-axis. With the x-axis, they make a 00or 1800 angle, and with the y-axis, they form a 900 or 2700  angle.

Vertical line- A line drawn vertically is called a vertical line, it is mainly drawn parallel to the y-axis and perpendicular to the x-axis. With the y-axis, they make a 00or 1800 angle, and with the x-axis, they form a 900 or 2700  angle.

Oblique or Slanted lines- The lines which are drawn diagonally are called Oblique or Slanted lines. It makes many angles other than zero, ninety, one hundred eighty, two hundred and seventy.

Properties

Straight lines have their own merits which must be taken into account when using them, which are as follows;

• It is almost impossible to calculate the distance of a straight line between two extreme points because its length is infinite.
• Since the straight line has infinite length, it gives zero area, zero volume.
• It represents a one dimensional figure.
• A straight line does pass through two points, but we can represent an infinite number of points in it.

Equation Of a Straight Line 

The main relation of the equation of a straight line is that linear equation on which it can be represented differently on the basis of the known variables, angles and constants of a straight line on the Cartesian plane. Apart from this, it tells the slope of the straight line and also describes its direction. It is calculated based on the y coordinate and the x coordinate, also called run over run. The equation of a straight line can also be represented as follows;

A straight line’s general equation is ax + by + c = 0, where ax + by + c = 0.

• where a, b, and c are constants, and a, b, and c are variables.
• Variables are x and y.
• -a/b is the slope.

Slope and Y-intercept Form

If the slope of a straight line is m = tanθ, the angle formed by the line with the positive x-axis is provided by: y = mx + b, where m is the slope, and the y-intercept is given by: 

If, y = mx + b, where m is the slope.

Slope Point Form

If the slope of a straight line is m = tanθ, 

Slope Point Form as, where is the angle produced by the line with the positive x-axis and

passing through a point (x1, y1)