The Triangle #1
The Triangle in Leonardo da Vinci's Last Supper.
Whether the posture of Jesus, with his arms open before him, was intended to represent a triangle is debatable. There are plenty of good reasons to depict Christ in such a stance. It conveys, for one, a sense of calm and inner authority which contrasts sharply with the intense agitation of the disciples. Furthermore, Christ’s left hand, opening up in a gesture of offering, visually balances the movement initiated by his right hand as it turns towards the morsel of bread.
Nevertheless, if we were to extend downwards the triangle suggested by the posture of Christ (following the diagonals of the grid's modules), we would end up with a triangle of base 4 and height 2, with its apex at the centre of the grid.
And this, ladies and gentlemen, is the key to the geometry of The Last Supper!
From this single triangle, one can derive the height of the windows and door openings, the construction of the pediment above the door, and the placement of the cornice. Can you see how?
It is also possible to explain the position of the perspective lines suggested by the tapestries! And much more...