Learn about Parts of a Line In this problem, we need to name each figure. Let’s take a look at Figure A. Figure A shows a straight path. There are two arrows at the end of each. These arrows indicate that the straight path goes on forever. When you see an arrow, it tells you that the straight path goes on forever in both directions. A straight path that goes forever in both directions is a line. So, a straight path that goes on forever is called a line. It goes on forever in both directions. Please note though that lines that go on forever in the left and right direction such as this is called a horizontal line. However, lines that goes up and down such as this is a vertical line. So, A is called a line because it’s a straight path that goes on forever in both directions. Let’s take a look at B. B shows a straight path. However, there are two end points. Any time you see a dot or a period at the end of the line; that is called an end point. The endpoint indicates that the path does not go on forever in both directions. When you have an endpoint, it means that the path does not go on forever. When you have a straight path with two end points such as this, it is called a line segment. That means this figure is a straight path with two endpoints, so that means it does go on forever which means this figure is a line segment. Let’s take a look at C. This Figure C shows a straight path. There is an endpoint and an arrow at the other side. Remember the arrow means it goes on forever. This arrow indicates that the line goes on forever in this direction while the endpoint shows that it ends on one side. So, any time you have a straight path that goes on forever in one direction and from an end point, it’s called a ray. This figure is named a ray. Thing to keep in mind, a straight path that goes forever in both directions is called a line. A straight path with two endpoints is called a line segment and a straight path that goes on forever in one direction from an endpoint is called a ray.