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Teacher Toolbox icon Teacher Toolbox - Facilitating the Build a 2D List Page

What the Teacher Will Do:

  • Instruct students that they will be working together in their groups to follow the steps on this page.
  • Circle the classroom as students work through these steps and answer any questions that arise.
  • As groups check in, ensure they have built their project and inserted their coordinate values correctly before moving on. Guidance for this check in is provided in a Teacher Toolbox at the bottom of this page.

For Your Information

A 2D (2-Dimensional) list, also known as a 2D Array, stores multiple sets of numeric values that are related. A 2D list can also be defined as a variable that contains other variables. A 2D list is made up of rows and columns.


  • Rows are horizontal.
  • Columns are vertical.


For the Workcell, a 2D list will be created and used to iterate the arm’s movement between the different coordinate points. The number of columns will represent the x, y, z-axis values of the coordinates and the number of rows will represent the number of stored (x, y, z) points.



x, y, z values

In VEXcode V5, follow the steps in this video to remove the [Set manual movement] block and build the Triangles 2D list. 

  • Since there are ten points needed to draw two triangles, you need 10 rows to store each coordinate point.
  • Since there are 3-axis values (x, y, z) for each of the 10 points, you need 3 columns to store the x, y, and z values.

For Your Information

An index is a numerical representation of an item's position in a list or sequence. Each row of the 2D list creates an index of a coordinate point.

Point 1 is represented by the first row of the 2D list with the first oval as the x-value, the second oval as the y-value, and the third oval as the z-value. This pattern continues for each of the rows in the 2D list.

2D List, point 1_0

Follow the steps in this video to add a [Set 2D list to] block to the project and input the coordinates of the ten triangle points.

Ensure you are using your triangle coordinates, and not the ones displayed in this video. 

Once you have finished inputting the coordinates, check in with your teacher.

Teacher Toolbox icon Teacher Toolbox - Check in

Review the following with the group during their check in:

  • Ensure groups added the 2D list and their coordinate values correctly.
    • Groups should have one 2D list with 10 rows and 3 columns.
    • All values in the list should correspond to the points recorded in their engineering notebooks on the previous page.

2D List, point 1_0_0