"This is a story of how harmless choices can make a harmful world," reads the introduction on playable post Parable of the Polygons. Just above this text, a crowd of yellow triangles and blue squares ...

A nonagon has nine sides and a decagon has ten sides. To understand polygons, a good understanding of other angle rules, including triangles and quadrilaterals can be helpful. The word for the name of ...

Help sort shapes in a shape factory. Look at examples of shapes to see if they belong in a polygon group, or set. Examine examples of shapes that do not belong in the set. What features do you think ...