President of Russia (Wikipedia)
The president of the Russian Federation (Russian: Президент Российской Федерации, tr. Prezident Rossiyskoy Federatsii) is the executive head of state of Russia. The president is the chair of the Federal State Council and the supreme commander-in-chief of the Russian Armed Forces. It is the highest office in Russia.- Pythagorean theorem (Wikipedia)
In mathematics, the Pythagorean theorem or Pythagoras’ theorem is a fundamental relation in Euclidean geometry between the three sides of a right triangle. It states that the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares on the other two sides.