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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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exponential function
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trigonometry
plane geometry
analytic geometry
solid geometry
combinatorics
probability
elements of statistics
kropki game

a, b, c, d - length of edges of a base, H - height. The pentagonal pyramid has 6 faces, 10 edges, 6 vertices. Angles in pentagonal pyramid. Regular pentagonal pyramid has in base square and its height drop directly onto center of the base. All three lateral faces of this pyramid are isosceles triangles. The volume and the surface find in the same way as all pyramids: V = 1/3A_bH, S = A_b + A_l. H - height, A_b - base area (pentagon), A_l - lateral surface area (sum of areas of triangles.