Basic Geo-tri-isometric quilt designs implicates playing on the doorstep of geometry with a variety of polygons to choose from. Each with a defined number of spokes. The spokes determine the outside shape, the triangle count and the angle at which the triangles meet in the centre.
The basic geo-isometric shapes are:
Triangles with 3 x 60° corners and 3 spokes
Squares with 4 x 90° corners and 4 spokes, usually drawn with 6 or 12 spokes
Pentagons with 5 x 72° corners, and 5 or 10 spokes. The even number of spokes ensures a circular design because five only needs an extra patch to complete the pentagon star or flower
Hexagons with 6 x 120° corners 0r 12 spokes, the most popular geo-isometric shape!
Heptagons with 7 x 51° corners
Octagons with 8 x 45°
Nonagons with 9 x 40°
Decagons with 10 x 36° corners and 10 spokes
The most popular polygon shapes are the triangle, square and the hexagon. The pentagon is a good example of how quilt makers have developed this shape into beautiful passacaglia quilts. It refers to the same patch being used for shared blocks, ex the green leaves for pieced flower blocks below. It appears as if one pieced block is positioned over another.