Rania is working with the city of Geocove to help them create the plans for their waterpark.

Her job is to design some of the pools that will be constructed in the park.

The pools will have different shapes, depths, and features.

Rania is currently designing two rectangular landing pools. The pools will each be at the bases of the larger splashbowl slides.

On a splashbowl slide, riders zip into bowl-like area where they spin around before being dropped into the pool below.

Since the riders will be exiting the bowl very fast, the bottom of the landing pool must have zero slope at the point where the riders enter it.

Recall that slope measures the steepness of a line.

A line that has 0 slope is called a horizontal line. It is perfectly flat.

What else has a slope value of 0? Most desks or tabletops, portions of roads or sidewalks, parking lots, and the horizon line.

In this lesson, you will learn how to calculate the slope of both horizontal and vertical lines.

You will also learn how to use the graph of a line to state whether the slope is positive, negative, zero, or undefined.