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numbers and algebraic expressions
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function and its properties
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polynomials
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logarithm
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trigonometry
plane geometry
analytic geometry
solid geometry
combinatorics
probability
elements of statistics
kropki game

The perimeter of a polygon we get add length of all sides. Examples. P = 4 + 2 + 3 = 9. P = 4 * 3 = 12. P = 2 * 5 + 2 * 3 = 10 + 6 = 16. P = 4 + 5 + 1 + 3 + 2 = 15.