Question

9.) List three things vertical and horizontal lines have in common.

Answer 1

Answer:

Horizontal lines have a slope of zero, and run parallel to the x axis. Vertical lines have a undefined slope, and run parallel to the y axis. The equation for a horizontal line equals y=c, and the equation for a vertical line equals x=c. If a horizontal line crosses a vertical line the two lines would be perpendicular to one another.

Step-by-step explanation:

Answer 2

Use this:

What is a Horizontal Line?

A Horizontal Line is a line that goes straight from left to right (or right to left)  parallel to the x-axis of the coordinate plane. All of the points on the line will have the same y-coordinates.

What is a Vertical Line?

A Vertical Line is a line that goes straight up and down Parallel to the y-axis of the coordinate plane. All of the points on the line will have the same x-coordinates.

Commonality:
Any vertical line is defined as perpendicular to any horizontal line.