GeoGebra Worksheet: COPYING A LINE SEGMENT AND AN ANGLE

GeoGebra an be used to "simulate" a hand construction, by using only the circle and segment tools.

COPYING A LINE SEGMENT

  1. Uncheck VIEW-AXES.

  2. Select OPTIONS-LABELING-NEW POINTS ONLY, so that only new points will be labeled.

  3. Create a segment to copy; name the endpoints A and B.

  4. Create a line to hold the copy of the segment.
    Hide the two points used to create this line.

  5. Put a point on your line; this will be an endpoint of your copied segment.
    Rename this point A'.
    You should now be looking at something like this:

  6. Use the "Circle with center and radius" tool to construct a circle with center A', and radius equal to the length of your original segment.
    (You may need to figure out what GeoGebra is calling the length of your original segment.)

  7. Create the intersection point of this circle with the line containing A'.
    Rename this intersection point B'.

  8. Hide the line and circle.
    Create the line segment from A' to B'.
    Change the length of the original segment, and make sure the copy follows accordingly!

  9. Create the dynamic text shown below:


COPYING AN ANGLE

  1. Select FILE-NEW to start a new drawing.

  2. Uncheck VIEW-AXES.

  3. Select OPTIONS-LABELING-NEW POINTS ONLY.

  4. Use the ray tool to create an angle to copy.
    The vertex should be labeled A.
    The point on the upper side should be renamed P;
    this point will be used later to change the original angle.
    Hide the point on the lower side.
    You should be looking at something like this:

  5. Create a line to hold one side of the copy of the angle.
    Hide the two points used to create this line.
    Put a point on this line; this will be the vertex of the copied angle.
    Label this new vertex A'.
    You should now be looking at something like this:

  6. Pick an appropriate radius (say, 2) and use the "Circle with center and radius" tool to construct a circle with center A.
    Use the same radius to construct a circle with center A'.
    You should now be looking at something like this:

  7. Create the intersection points E, F, and G shown below:

  8. In the "Input:" field, type "r = distance[E,F]" (do NOT type the quotation marks) and press ENTER.
    You are finding the distance from E to F, and calling it  r .

  9. Use the "Circle with center and radius" tool to create the circle with center G and radius r.

  10. Create the intersection point H shown below:

  11. Construct your copied angle.
    Clean everything up, hiding all auxiliary objects.
    Make sure that as you move point P, your copied angle follows accordingly!

  12. SAVE your GeoGebra file with YOUR NAME, like this:
Bart_Simpson_02.ggb

-- Be sure to put the ".ggb" extension.
             -- Use an underscore between your first and last name and then an underscore and 02.
             -- EMAIL this file to me (as an attachment).

  1. This assignment is worth 10 points.
    -- It is due on WEDNESDAY, SEPTEMBER 8, by 12PM.