1.1 - 1.2 Practice and Constructions

Let's Practice!

This GeoGebra activity will act as a review over sections 1.1 and 1.2. We will practice naming lines, rays, and planes. Then we will practice using the Segment Addition Postulate to solve problems. Lastly, we will learn how to copy a line segment on GeoGebra.

Naming

Below, you will see different geometric figures. Use the figure that is ABOVE the question to answer the question.

Lines

Use points to name the line that goes through point G. You do NOT need to include the correct symbol at this time.

Which of the following symbols should go with the name of your line?

[math]\longrightarrow[/math] No Symbol ___ [math]\longleftrightarrow[/math]

Rays

Name the 2 rays in this image. You do NOT need to include the correct symbol at this time.

Which of the following symbols should go with the name of your line?

___ [math]\longrightarrow[/math] No Symbol [math]\longleftrightarrow[/math]

True or false. [br]The order that I list the points does NOT matter.

True False

Planes

Name the plane shown above.

Which of the points are NOT coplanar with the plane shown. Select all points that are not coplanar.

I G E J F H K

Segment Addition Postulate

Points A, B, and C are collinear. What is the length of segment AB?

Points D, E, and F are collinear. What is the length of segment FE?

Copying a Line Segment

Last week, I demonstrated how to copy a line segment using a compass and straightedge. Now, I will walk you through copying a segment on GeoGebra.[br][br][list=1][*]Use the "Line Segment" tool to draw a segment. It will be easiest if you make your segment take up 1/2 to 2/3 of your screen (so basically, don't make it super long or super short)[/*][*]Find the "Compass" tool in the circle menu and click it[/*][*]Click on one endpoint of your line segment, then click on the other endpoint (this is like me placing the pointy side of my compass on one endpoint and my pencil on the other)[/*][*]You will now have a circle with a radius that is the same length as your line segment. Move your mouse so that the circle isn't touching your segment[/*][*]Click to drop your circle[/*][*]Select the "Point" tool and place a point on your circle[/*][*]Use the "Line Segment" tool to connect the center of your circle to the point you placed on your circle[/*][/list]You're done! The segment that you just drew is the exact same length as your original segment.

Does it matter where you place your point on the circle? Why or why not?