App description

Quadrangular pyramid, positive pyramid If the bottom surface of a pyramid is a regular polygon, the bottom may have 3 or more edges. Also called a polygonal pyramid.

(1) The sides of the regular pyramid are equal, each side is a congruent isosceles triangle, and the height of the base of each isosceles triangle is equal (it is called the oblique height of the regular pyramid);

(2) The height, the oblique height and the oblique height of the regular pyramid form a right-angled triangle in the bottom surface, and the projections of the height, side edge and side edge of the regular pyramid in the bottom surface also form a right-angled triangle;

(3) The angle formed by the side edge of the regular pyramid and the bottom surface are equal; the dihedral angle formed by the side surface of the regular pyramid and the bottom surface are equal;

(4) Side area of the regular pyramid: If the circumference of the right pyramid is c and the height is h', then its side area is s=1/2ch

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