why pyramid's name is pyramid?

A pyramid (from Greek πυραμίδoς - pyramidos, genitive of πυραμίς - pyramis) is any three-dimensional polyhedron where the faces other than the base are triangular and converge on one point, called the apex. The base of a pyramid can be any polygon but is typically a square, leading to four non-base faces.
A pyramid is said to be regular if its base is a regular polygon and its upper faces are congruent isosceles triangles.
Cutting off the top of a pyramid, using a plane parallel to the plane of the base, leaves a frustum of a pyramid, sometimes called a flat-topped pyramid, though it no longer satisfies the definition of a pyramid.





Contents

1 Ancient monuments

1.1 China
1.2 Egyptian pyramids
1.3 France
1.4 Greece
1.5 India
1.6 Mesoamerican pyramids
1.7 Mesopotamian pyramids
1.8 North American pyramids
1.9 Nubian pyramids
1.10 Rome
2 Medieval Europe
3 Modern pyramids

3.1 Gallery
4 References
5 External links



Ancient monuments

See also: List of ancient pyramids by country
Pyramid-shaped structures were built by many ancient civilizations.

China


Main article: Chinese pyramids
There are many flat-topped mound tombs in China. The First Emperor of Qin (circa 221 B.C.) was buried under a large mound outside modern day Xi'an. In the following centuries about a dozen more Han Dynasty royals were also buried under flat-topped pyramidal earthworks.

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有詳細中文解釋

2008-04-14 18:48:44 補充：
我答遲了，只有發表意見吧。