# The Slope of a Line: Types of Slopes

Generally, there are three types of slopes of a line:

**Positive, Negative, and Zero**

The fourth one on this list is really not considered a type of slope because it is the situation wherein the line has no slope. This is usually referred to as undefined because the denominator or the change in variable “x” is zero.

Check out how **Mr. Piggy** can help you remember this concept!

**I. Positive Slope**

A **positive slope** means the line is **increasing** when viewed from left to right.

As you can see, Mr. Piggy is having a hard time going up since it costs him an extra effort for an uphill climb.

**II. Negative Slope**

A **negative slope** means the line is **decreasing** when viewed from left to right.

Thanks to gravity, Mr. Piggy is definitely enjoying the slide because it takes him less effort to go down.

**III. Zero Slope**

A **zero slope** means the line is neither increasing nor decreasing when viewed from left to right, or vice versa.

Mr. Piggy is free to showcase his running skills on this level ground.

**IV. Undefined Slope or No Slope**

An **undefined slope** or **no slope** means the line is neither moving to the left nor to the right such as a vertical line.

In this situation, Mr. Piggy will experience the endless “fall” of his lifetime!

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