Here is Piero di Cosimo’s depiction of the Virgin and Child adored by saints including Elizabeth of Hungary, at left, and Catherine, at right.
The panel is a perfect square. Note that a circle inscribed within this square swings tantalizingly along the side of the cloud at upper left and the putto’s wing, at right. This circle can be understood as just the first in a sequence of compass-drawn quadrature steps
The base of the orange square inscribed within the red circle coincides with the edge of the lowest step on the Virgin’s throne, and the left and right midpoints of that square locate the hands of Saints Peter and John, who flank the composition. Here also rays have been added subdividing the composition into 24 equal wedges; note that these align with elements including the outer visible tiles in the floor in front of the throne.
Continuing inwards, further concentric circles divide the saints into ranks of proximity to the Child
Only Elizabeth and Catherine, for example, have faces within the green square.
And only Catherine’s hand penetrates into the blue circle that frames the child.
The bend of her fingers aligns with the same violet square that frames the child’s leg, and her fingertips penetrate just beyond the circle that frames his shoulder.
The horizon line can also be readily found within this framework, as can the curving top edge of the Virgin’s throne.
This painting is the property of the John Museo degli Innocenti, Florence, Italy. This analysis was based on the image: