Three-dimensional geometric figures: All kinds of figures abstracted from physical objects are collectively called geometric figures, and geometric figures are one of the main objects of mathematical research. Some geometric figures (such as cuboid, cube, cylinder, cone, sphere, etc. ) are not on the same plane, they are all three-dimensional graphics. A three-dimensional figure surrounded by one or more possible faces in real life. Points become lines, lines become faces, and faces become bodies. That is, an object is surrounded by faces, and an object can see at most three faces of a three-dimensional graphic object. Common solid geometric figures and their properties: ① Cube: with 8 vertices and 6 faces. Each face has the same area (or each face is made up of squares). There are 12 sides, and each side is equal in length. (Cube is a special kind of cuboid) ② Cuboid: It has 8 vertices and 6 faces. Each face consists of a rectangle or a set of opposite squares. There are 12 sides, and the four opposite sides are equal in length. ③ Cylinder: The upper and lower surfaces are circles with the same size. There is a face called a side. When expanded, it is rectangular, square or parallelogram. There are countless kinds of heights, all of which are of equal length. ④ Cone: It has 1 vertices, 1 faces and a bottom. It is fan-shaped when unfolded. Only 1 bar high. A tetrahedron has 1 vertices and six sides. ⑤ Straight triangular prism: a triangle with three tangent sides and two parallel and congruent upper and lower sides. ⑥ Ball: Ball is one of the most common figures in life. For example, basketball and football are balls, and the ball is a geometric body surrounded by curved surfaces. Common three-dimensional geometry views: geometry cuboid cube cone cylinder cone sphere