Radius
The surviving page identifies Radius as an interactive art piece and places the familiar circle-area formula beside it. It invites the audience to discover how the work operates.
A deliberately open-ended interaction
The capture supplies little mechanical detail. The historical record therefore preserves the invitation to investigate without inventing a sensor, a movement mechanism, or a complete explanation of the interaction.
Historical evidence
This is an independently written historical record. Original project authorship and rights remain with their respective creators. This edition does not offer the former owner’s services.