Isosceles triangle

Ruthlessly mocking Bloom's romantic stereotype of Spaniards, Italians, and other Mediterranean peoples as hotblooded types, Stephen lobs some counter-examples in Eumaeus: "we have the impetuosity of Dante and the isosceles triangle, Miss Portinari, he fell in love with and Leonardo and san Tommaso Mastino." The Trinitarian numerology of Dante Alighieri, the serene mathematics of Leonardo da Vinci, and the massive logic of Thomas Aquinas all would suggest that an Italian can be just as cerebral as the next guy.

JH 2018

William Blake's etching of Beatrice and Dante before the three beasts that block his ascent toward the sun in Inferno canto 1, most likely an allegory for the three categories of sin that he will face in Hell. Source: eponymistuk.blogspot.com..

Beatrice and Dante before the three Persons of the Holy Trinity, in a 15th century manuscript by Giovanni di Paolo held in the British Library. Source: Wikimedia Commons.

The nine celestial spheres of Ptolemaic cosmology which Dante maps onto the nine orders of angels contemplating God in the Empyrean, in figure 5 in the 1986 Penguin Paradiso translated by Mark Musa.

Vitruvian Man, ca. 1490, pen and ink with wash on paper, from a notebook of Leonardo da Vinci, held in the Gallerie dell'Accademia, Venice, photographed by Luc Viatour in 2007. Source: Wikimedia Commons.