Crows can recognize geometric patterns, suggesting that humans aren't unique in understanding shape structure.

For example a cube has 12 edges ... Look at how these shapes have been sorted. Remember a quadrilateral is any shape with 4 straight sides. Now the shapes have been sorted using a Venn diagram.

This fact is a more specific example of the equation for calculating ... of a polygon is to see how many triangles the shape is composed of. Quadrilaterals are composed of two triangles.