English: Three cones of light of different widths and intensities, generated by a downwards-pointing halogen lamp and its holder, are drawing three hyperbolic curves on a nearby vertical wall.
Italiano: Tre coni di luce di diverse ampiezze e intensità, generati da una lampada alogena rivolta verso il basso e il suo portalampada, disegnano tre iperboli su un vicino muro verticale.
Français : Lorsqu'une lampe est placée non loin d'un mur vertical, la courbe qui délimite, sur le mur, la zone éclairée et la zone ombragée est un arc d'hyperbole.
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