Laying (linked) pentagonal tiles - trouble snapping I am pretty new to Blender, having previously used Form•Z Free (which is pretty good for modelling when it doesn't crash). 

I am looking to tile a 'floor' in Blender 2.8, using a pentagonal tile (this is a Kershner (1968) type 6 pentagon, derived lengths and angles given by the excellent java applet at https://www.jaapsch.net/tilings/applet.htm)

Trying to rotate and align the tiles (which are linked instances, and need to be, for subsequent transforms) is proving really difficult.  I managed to get the 3D cursor to a vertex, and I can change just 1 vertex to be the origin, but if I then change the origin - every tile moves according to the new origin values.

There must be an intuitive way of getting the tiles to snap together correctly - (I am struggling with both move and rotate)

The file - to play with as you like!


Just in case you are unsure about how they tile...
You can get there using vertex snapping and some manual rotation.  


Make your base tile a single face pentagon. Remove double vertices (there are some).
Don't use object instances yet, you'll convert them all in the end. Just copy new tiles now.
The main angle is 71°. Type the equations directly into the rotation field.
Enable Vertex Snapping > Median. Origin points will now snap to vertices.
Put your origin to different vertices if needed.  


Convert tiles into instances


Select all objects and go Object > Set Origin > Origin to Geometry. This will keep them in place.
Select all tiles and turn them into instances Object > Make Links > Object Data


The main face angle is 71°



Type equations into the Z rotation field.



Use Vertex Snapping > Median to snap origin point to vertices. Move the origin point if needed.



Make all tiles into instances of one. But make their origin points centered first.