Lesson 3: Grid Moves

What do you notice? What do you wonder?

Follow the directions below each statement to tell GeoGebra how you want the figure to move. It is important to notice that GeoGebra uses vectors to show translations. A vector is a quantity that has magnitude (size) and direction. It is usually represented by an arrow.

These applets are sensitive to clicks. Be sure to make one quick click, otherwise it may count a double-click.

After each example, click the reset button, and then move the slider over for the next question.

1. Translate triangle $ABC$ so that $A$ goes to $A’$.
   1. Select the Vector tool.
   2. Click on the original point $A$ and then the new point $A’$. You should see a vector.
   3. Select the Translate by Vector tool.
   4. Click on the figure to translate, and then click on the vector.

2. Translate triangle $ABC$ so that $C$ goes to $C’$.

3. Rotate triangle $ABC$ $90^\circ$ counterclockwise using center $O$.
   1. Select the Rotate around Point tool.
   2. Click on the figure to rotate, and then click on the center point.
   3. A dialog box will open; type the angle by which to rotate and select the direction of rotation.
   4. Click on ok.
4. Reflect triangle $ABC$ using line $\ell$.
   1. Select the Reflect about Line tool.
   2. Click on the figure to reflect, and then click on the line of reflection.

5. Rotate quadrilateral $ABCD$ $60^\circ$ counterclockwise using center $B$.
6. Rotate quadrilateral $ABCD$ $60^\circ$ clockwise using center $C$.
7. Reflect quadrilateral $ABCD$ using line $\ell$.
8. Translate quadrilateral $ABCD$ so that $A$ goes to $C$.