Geometric Triangle Ratios

In the twilight, you can recognize multiple planes on the human face arranged in a triangle. Which planes you see depends on your viewing angle, the angle of light falling on the face, or the shadows.
With regard to basic forms of patterns on the (female) face, such as discs or spheres, the following models of triangulations can be distinguished:

Eye-Mouth-Eye Triangle

Two eye sockets and the mouth.

For example, it can sometimes be seen that the mouth forms a dark spot, which is approximately the same size as each of the two eye sockets. The three dots (at the center of each plane) can together form an equilateral triangle. Several variations in the design are possible.

Image A: Abstract picture of Eye-Mouth-Eye triangle pattern.

Cheekbone-Chin-Cheekbone Triangle

Two cheekbones and the chin.

Depending on the light intensity or angle of incidence, you can observe 3 light spots positioned in a triangle relative to each other: the shiny surfaces of the two cheekbones together with the chin having the same size.

Photo B: Triangle pattern of Cheekbone-Chin-Cheekbone
(Photographer: Martin.que ; License of Pexels.)
(The Nose-face has the same size as an eye socket.)

Eye - Nose Bulb - Eye Triangle

Two eyes and the tip of the nose.

Another triangle involves the points between: left eye - nose - right eye. This triangle is usually not equilateral.

Photo C: Triangle pattern of Eye-NoseBulb-Eye. (Photo by Dmitriy Ilkevich ; see Unsplash License)	Image D: Nose-Bulb (green circle) has equivalent size as the nose-bulb & irises of the woman at the left.

I will explain the evolutionary phenomenon of the nose-bulb as facial gestalt later on.
For now, it is important to acknowledge that triangle geometry is common in face shapes.