When you do not understand something and just miss it out.
It is a tessellation which uses two regular polygons. For example, octagons and squares.
There is no such thing as a seni-regular tessellation. A semi-regular tessllation is a tessellation using two regular polygons: for example, octagons and squares together.
A non-repetitive pattern.
A tiled bathroom is one example.
Spheres defy 3D tessellation. There is no way to pack spheres so that there is no gap between them.
Tessellations are named based on the number of polygons located at a vertex. For example: A regular tessellation, made from only triangles is named 3.3.3
Yes. For example a chess board.
Tiled bathrooms and paved areas are common example.
A regular pentagon is one example.
Yes it is a tessellation.
A simple tessellation is a pattern made of identical shapes. The shapes fit together without any gaps and do not overlap. An example of a simple tessellation would be a tiled floor.
Non-visible tessellation or non-existent tessellation, perhaps.