## EXPRESSING DEFINITIONS AND THEOREMS

Keywords - Geometry, algebra.

Purpose - Improving the capacity to express a definition, theorem, etc.

Didactic materials - A 2m x 2m black cloth.

Description - Participants are divided into pairs. Each couple selects

what they want to express from definitions, theorems, axioms, etc.

To express their own concept, one person may use their hands and the other words. One of the pair is sitting in a chair while the other is kneeling behind the partner and passes her/his arms under the underarms of the person sitting. The person seated puts her/his arms behind the back of their partner.

Brought together in this way, the two components will be able to “speak” helping each other: the seated one can talk, the kneeling one can move her/his arms and gesticulate in sync with the words said by the partner. To render the situation more effective it is important to cover the body of the seated person with the cloth so the arms of the kneeling person stick out of it. The kneeling person must also hide their head from the public lowering it behind the back of the seated partner.

Each pair has 10 minutes to decide which concept to express to the public, assign the roles within the pair and decide how to coordinate the voice of one and the gestures of the other during the presentation.

The trainer explains the context within which the action will take place to the group: we are at an international conference and finally, after waiting for many years, a secret will finally be revealed that will revolutionise the state of modern mathematics.

Each pair presents their concept, the trainer plays the presenter and the group is the public at the above-mentioned conference.

Duration - A minimum of 45 minutes.

Observations - The role of the presenter played by the trainer is very important in this case. Making the conference situation theatrical will foster the public’s and orators’ enjoyment.