Introduction to Pyramid 04.30
棱锥体简介 04.30
Objectives
学习目标
· To learn the concept of a pyramid
· 学习棱锥体的概念
· To understand different types of pyramids
· 了解不同类型的棱锥体
· To learn the terminology associated with a pyramid
· 学习与棱锥有关的术语
We are all familiar with the famous pyramids of Egypt. These monumental structures have stood there for centuries and have left the tourists and archaeologists, the world over, in awe by their sheer architectural grandeur.
我们都熟悉埃及著名的金字塔。这些伟大的建筑几个世纪以来屹立在那里,令世界各地的游客和考古学家对它们的宏伟庄严无不叹为观止。
In the realm of geometry, a pyramid is a polyhedron formed by connecting a polygonal base and a point, called the apex or vertex outside the plane of the polygon. The end points of each base edge and the apex form a triangle. It is a conic solid with a polygonal base.
在几何学领域中,棱锥是一个通过连接多面体底面和一个底面外的点(称为顶点或端点)形成的多面体。每个底边的端点和顶点连接形成一个三角形。它是一个有着多边形底面的圆锥。
The square pyramid, with a square base and four triangular outer surfaces, is a common version. When unspecified, the base is usually assumed to be a square. A pyramid with an n-sided base will have n + 1 vertices, n + 1 faces and 2n edges.
四角形棱锥,有一个正方形底面和四个三角形外表面,为一般类型。未特别指定时,底面通常认为为正方形,一个底面有n个边的棱锥有n加1个端点,n加1个面和2n个边。
Parts of a Pyramid
棱锥的组成部分
A pyramid is made by connecting a base to an Apex.
一个棱锥是通过连接底面和顶点形成的。
Types of Pyramids
棱锥的类型
There are many types of Pyramids and they are named after the shape of their base.
棱锥有多种类型并根据它们底面的形状命名。
Triangular Pyramid:
三棱锥:
This pyramid has a triangle at its base. It has four faces including the base, four vertices and six edges.
这种棱锥的底面为一个三角形,有包括底面的四个面,四个端点和六条边。
Pentagonal Pyramid:
五棱锥:
This pyramid has a pentagon as its base. It has six faces including the base, six vertices and ten edges.
这种棱锥底面为一个五边形。它有包括底面在内的六个面,6个端点和10条边。
Right and Oblique Pyramid
直棱锥和斜棱锥
This tells us as to where the top or apex of the pyramid lies. If the apex is directly above the centre of the base, then it is a Right Pyramid, otherwise it is an Oblique Pyramid.
此名称表明了棱锥顶端或顶点的所在位置。如果顶点在底面中心的正上方,那么它是直棱锥,否则为斜棱锥。
Regular and Irregular Pyramid
正棱锥和不规则棱锥
This tells us about the shape of the base. If the base is a regular polygon, then it is a Regular Pyramid, otherwise it is an Irregular Pyramid.
此名称表示底面的形状,如果底面为正多边形,那么这是一个正棱锥,否则为不规则棱锥。
Terms associated with a pyramid:
与棱锥相关的术语:
The base is a polygonal face that is opposite to the vertex or Apex. The lateral face is the face of a pyramid that is not the base. Vertex of a pyramid is a point where all the lateral triangular faces meet. It is also called the Apex of the pyramid. The Base edge is the line where each lateral face meets with the base. Lateral edge is the intersection of two lateral faces of a pyramid. Altitude of a pyramid is the perpendicular line segment from the vertex to the plane of the base. Height is the length of the altitude. A regular pyramid is a pyramid whose base is a regular polygon and whose lateral faces are congruent isosceles triangles. The slant height is the length of an altitude of the lateral face of a regular pyramid.
底面是一个与顶点或端点相对的面。侧面是非底面的面,棱锥的顶点是所有三角形面会和的点。也被称为棱锥的端点。底边是每个侧面与底面相交的线。侧边指棱锥两个侧面的交汇处。棱锥的高指从顶点到底面的垂直线段。高度指高的长度。正棱锥指底面为规则多边形且侧面为全等等腰三角形的棱锥。斜高指正棱锥的侧面的高度。
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