In 1820, German mathematician Karl Friedrich Gauss proposed cutting an enormous right triangle into the Siberian pine forest, creating a monument to the Pythagorean theorem big enough to see from outer space.

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Behind the velodrome's timber-clad frame, cyclists will race for gold round a track made from sustainably-sourced Siberian pine, while Zaha Hadid's striking wave-shaped roof on the Aquatics Center has been temporarily adorned with "wings" providing seating for 15, 000 spectators.

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