Angle Pairs in an Islamic Lattice

This is an Islamic Lattice pattern from Alan D Adams (on flickr.com). It is identical in design to one at the tomb of an Asian conqueror, Timur, in what is now Uzbekistan. The tomb was the model for the great Taj Mahal in Agra, built by Timur's descendants, the ruling dynasty of North India. Use the construction and transformation tools to demonstrate relationships between pairs of angles. Because Mr. Adams is so careful, you may assume that lines appearing parallel are parallel.
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