Assertion: polyhedron's triangle | /r/HasProperty | regular
Facets:
Source sentences:
text: A polygon is called regular if all of its sides are the same length, and all the angles between them are the same; the triangle and square in figure 1 and the pentagon in figure 2 are regular.
text: Triangles, squares, and hexagons are regular polygons that tessellate by themselves.
text: Based on this 2-D case [and, to a lesser extent, on the 3-D case] it would seem that such an inner ball [disk, sphere, or n-dimensional hypersphere] would always be small enough to fit inside the simplex [equilateral triangle, regular tetrahedron, n-dimensional regular simplex] formed by the centers of the congruent balls.