where the breadth of the pyramid of shadow is greater than the breadth of the pyramid of light.
At the point a the pyramid of light is equal in strength to the pyramid of shadow, because the base f g is equal to the base r f. At the point d the pyramid of light is narrower than the pyramid of shadow by so much as the base s f is less than the base f g.
Divide the foregoing proposition into two diagrams, one with the pyramids of light and shadow, the other with the pyramids of light [only].
261.
Among shadows of equal depth those which are nearest to the eye will look least deep.
262.
The more brilliant the light given by a luminous body, the deeper will the shadows be cast by the objects it illuminates.