The activity is about designing a 3-sided die, figuring out what shape it could be, printing it and after that trying it in order to check if the faces are equiprobable.

1) To figure out the possible shape of a die with 3 faces

2) To design the die with Tinkercad

3) Try the printed die to see if it works as expected

The teacher must guide the students to a possible design of the die in order to avoid frustration. One possibility is a cylinder with a concrete height; another could be a triangular pyramid with its central edges smoothed; another could be a triangular spinning top.

The teacher explains the objectives of the activity and organises students into groups. The design is up to the groups. The teacher explains the basics of Tinkercad and Cura.

1. The groups obtain a design for the die.

2. The groups proof (with calculations) that the die is fair.

3. The dice are printed.

4. The printed dice are checked to see if they are fair or biased.