Point is a plane figure, which is the simplest basic figure in the plane figure. A closed geometry surrounded by four or more planes is a polyhedron.
Solid geometry can be divided into the following categories:
(1) cylinder: including cylinder and prism. Prisms can be divided into straight prisms and oblique prisms, and can be divided into triangular prisms, quadrangular prisms and n prisms according to the number of sides of the bottom.
(2) Cones: including cones and pyramids, which are divided into triangular pyramids, quadrangular pyramids and N pyramids.
(3) Rotating body: including cylinder, frustum, cone, sphere, spherical crown, bow ring, circular ring, dike ring, fan ring, jujube pit, etc.
(4) Section: including frustum, frustum, truncated cylinder, truncated prism, truncated cone, spherical crown, spherical notch, etc. Its surface area and volume are generally solved by digital addition and subtraction.
Plane geometry can be divided into the following categories:
(1) circle: including perfect circle, ellipse and multifocal circle-ellipse.
(2) Polygons: triangles, quadrangles, pentagons, etc.
(3) Bows: excellent bows, poor bows, parabolic bows, etc.
(4) Multi-arcs: crescent moon, pattern, Tai Chi, gourd, etc.
Extended data:
Plane figure is a kind of geometric figure, which means that all points are on the same plane, such as straight line, triangle and parallelogram. Are basic plane figures.
Geometric graphics are widely used, and they are needed in design, painting creation and mathematical research.
Mathematical definitions, theorems, etc. It is very abstract in mathematical language, and theorems are difficult to remember, so it is an important link in teaching to help students remember and define theorems. If geometric figures and numbers are properly combined in teaching, students can deepen their understanding of intuitive figures and master their theorems.
Parallelogram is defined as two groups of quadrilaterals with parallel opposite sides, so the quadrilaterals, parallelism and opposite sides should be defined first. When defining a quadrilateral, define polygons and edges first, then polylines, so define points and lines first.
But in general elementary geometry, points and straight lines can no longer be defined by defined concepts, they are all original concepts. In mathematics, point, line, surface, set, space, number and quantity are all original concepts, but some of them are directly described by axioms. Although some concepts are also explained in middle school textbooks, this explanation is not a definition.
In the related branches of geometry, topology and mathematics, points in space are used to describe 1 kind of special objects in a given space, and there are similarities in volume, area, length, width and height in space. 1 point is 1 0-dimensional object. As the simplest graphic concept, point is usually the most basic component in geometry, physics, vector graphics and other fields.
References:
Baidu Encyclopedia-Geometry
References:
Baidu Encyclopedia-Plane Graphics