Point the Ray

Key Question: How are lines, line segments, and rays different? Learning Goals: The student will: Model and compare parallel and intersecting lines, line segments, and rays

Point the Ray Materials A Look at Lines Journal

Point the Ray  point

line A line is made of an infinite number of points. A line goes on forever in both directions.

Turn to the first page on your Looking at Lines Journal. Draw a point and a line in the correct box. In your own words, describe what a point and a line is.

What would happen if I took a piece of the line out of the center?

This piece or segment of the line would not go on forever.

It should not have arrows at each end but points to show that it stops. Mathematicians call these stopping points endpoints.

What do you notice about what is drawn below? What does the arrow on one end mean? What does the end point on the other side mean?

Turn to the next page on your Looking at Lines Journal. Draw a line segment and a ray. In your own words, write about the line segment and ray.

What do you notice about these two lines? They go on forever in both directions. They are always the same distance apart. These lines are called parallel lines. Can you find examples of parallel lines in the classroom?

What do you notice about these two lines? These lines meet or intersect each other. They are called intersecting lines.

Are these two lines intersecting lines? Why? These lines will meet or intersect each other because by definition lines go on forever.

Turn to the next page on your Looking at Lines Journal. Draw and write about parallel and intersecting lines.

What kind of lines are these? They are a special kind of intersecting lines because they form a right angle where they intersect. Can you find examples of perpendicular lines in the classroom? They are called perpendicular lines.

Point the Ray Part 2 Materials String, 2 meters for each pair Black construction paper arrows We will move to a large area where you will model lines, line segments, rays, and intersecting lines using the materials.

Point the Ray Describe a point. Describe a line. Describe a line segment. Describe a ray. Describe parallel lines. Describe intersecting lines. Describe perpendicular lines.