Google Classroom
GeoGebraGeoGebra Classroom

Nadir Divanbegi Khanagah - gp

The Nadir Divangegi Khanagah (1619-1623) is a sufi lodge, or retreat, located at the west end of the Lyab-i Hauz ensemble in central Bukhara. It was established in the 1620s by vizier Nadir Divan-begi, the maternal uncle of Imam Quli Khan, the ruler of Bukhara from 1611-41. The khanqah is one of a trio of buidings erected around a pond, or hauz, that gives the ensemble its name (Lyab-i Hauz means "by the pond" in Persian). The line pattern on the spandrel is constructed with dodecagons, enneagons and ties, just as the spandrel of the eastern iwan of the Kalon mosque.
Image
The difference between both is the arrangement of the paatern on the spandrel (See figure 1). The Kalon pattern is slightly magnified.
  • Now there's just one half dodecagon instead of two.
  • Along the lower edge there's a enneagon in both corners as welkl as in the middle.
  • As a result the pattern of the Nadir Divanbegi Khanagah has got less but greater stars.
Fig. 1
Left: spandrel of the eastern iwan of the Kanon mosque 
Right: spandrel of the Nadir Divanbegi Khanagah.
Fig. 1 Left: spandrel of the eastern iwan of the Kanon mosque Right: spandrel of the Nadir Divanbegi Khanagah.

a kite in the kites

Look at figure 2: Drawing a line from a point of the star, it doesn't run through another point of the star, in other words: in the real patterns the middles of edges aren't connected to one another. Why not? The reason is simple: the drawn pattern needs a kink to result in a kink within the tie which is not likeable.
Fig. 2
Fig. 2

the right pattern

To obtain kites within the ties we must reverse the logic. Don't start with the lines in the dodecagon but with those in the enneagon.
  • Define the middles of adjacent edges of a dodecagon and two enneagons.
  • Construct in both enneagons a line that belongs to a 9-3 star.
  • Draw the lines through the middle of the edge of the dodecagon and the middles on the enneagons and define for both lines the intersection with the corresponding 4th edge in the dodecagon.
  • This defines the top angle of the 12-ppointed star. Now you can construct a 9-3 star in the enneagons and in the dodecagon a star, so that lines create a kite within the ties.
You can follow the construction in the applet below.