# Pyramid–Also Known As Pyramid

### Product Description

**The base of the pyramid:** The polygon in the pyramid is called the base of the pyramid.

**Sides of a pyramid:** The faces of a pyramid other than the base are called sides of a pyramid. .

**Side edges of a pyramid: **The common edge of adjacent sides is called a side edge of a pyramid.

**The apex of the pyramid:**The common apex of the sides in the pyramid is called the apex of the pyramid.

**The height of the pyramid: **The distance from the apex of the pyramid to the base is called the height of the pyramid.

**Diagonal face of a pyramid:** The section of a pyramid that passes through two non-adjacent side edges is called a diagonal face.

### Characteristics

Pyramid is an important kind of polyhedron, it has two essential characteristics:

①One face is a polygon;

②The rest of the faces are triangles with a common vertex, and the two are indispensable.

Therefore, one face of a pyramid is polygonal, and the other faces are triangular. But also note that "one face is a polygon, and the rest of the faces are triangles" geometry is not necessarily a pyramid.

### Theorem

Theorem: If a pyramid is cut by a plane parallel to the base, the resulting section is similar to the base, and the ratio of the area of the section to the area of the base is equal to the square ratio of the distance from the apex to the section to the height of the pyramid.

Deduction 1: If a pyramid is cut by a plane parallel to the base, then the side edge and height of the pyramid are divided into the same ratio by the line segment.

Deduction 2: If a pyramid is cut by a plane parallel to the base, the ratio of the side area of the smaller pyramid to the original pyramid is also equal to the square ratio of their corresponding heights, or the ratio of their base areas.

● Shape tolerance: ±0.1mm

● Angle tolerance: ±3'

● Surface type: λ/4@632.8nm

● Finish: 40-20

● Effective aperture: >90%

● Chamfering edge: <0.2×45°

● Coating: Custom Design

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