- chris cambré
On all tiles the decorative lines intersect in the midpoint of the sides with angles of 72° and 108°. That's why all lines continue straight on over the tiles when you match two girih tiles. Since all sides of all sides are equal you've got many ways to match them. In the applet below you can drag the tiles and with the green points you can rotate them around the black points.
On https://girihdesigner.com you can experiment with girih tiles to create patterns. Or you can download next pdf-document and cut out the tiles to experiment yourself with matching possibilities.