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kropki game

Parallelogram is quadrangle that opposite sides are parallel. The perimeter of a parallelogram: P = 2a + 2b. The area of a parallelogram: A = ah, A = a*b*sinα. The angles in a parallelogram: α + β = 180°. The diagonals in a parallelogram. The point of intersection of diagonals O divides diagonals into equal parts.