Horizontal Line

A horizontal line is a straight line that runs parallel to the x-axis on a coordinate plane. It has a slope of 0 and is always at the same y-coordinate.

Characteristics of a Horizontal Line

Has a slope of 0.
Runs parallel to the x-axis.
Equation is in the form y = c, where c is a constant.

Graphing a Horizontal Line

To graph a horizontal line, plot points that have the same y-coordinate. Connect the points with a straight line to show that it is horizontal.

Examples

1. Graph the equation y = 3.

To graph y = 3, plot points (0, 3), (1, 3), (-1, 3), and so on. Connect these points to form a horizontal line parallel to the x-axis at y = 3.

2. Determine if the line with the equation y = -2x + 4 is horizontal.

The line with the equation y = -2x + 4 is not horizontal because it has a non-zero slope (-2).

Practice Questions

Graph the equation y = 5.
Determine if the line with the equation y = 2x - 1 is horizontal.

Summary

Horizontal lines have a slope of 0 and run parallel to the x-axis. Their equations are in the form y = c, where c is a constant. When graphing, all points have the same y-coordinate.

◂Math Worksheets and Study Guides Sixth Grade. Tables

The resources above cover the following skills:

Data Analysis and Probability (NCTM)

Select and use appropriate statistical methods to analyze data.

Discuss and understand the correspondence between data sets and their graphical representations, especially histograms, stem-and-leaf plots, box plots, and scatterplots.