Prisms are geometric solids defined in three-dimensional space from a polygon is straight. the set of parallel line segments to the line r whose endpoints are the given polygon and any plane that does not contain this polygon is called a prism. One example the final shape of this solid and how the line segments behave in this definition can be found in the following image:
prism elements
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prism bases: can be any polygon, like triangles, squares, pentagons, quadrilaterals etc. The only rule is that they must be congruent;
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prism faces: Any polygon that borders a prism is one of its faces;
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Side faces: Any face that is not a base. Every side face of a prism is a parallelogram, because the plane and the polygon are parallel, which makes a pair of opposite sides of these faces parallel. The other pair of opposite sides is parallel because they are segments parallel to the line r;
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Edges: are the straight lines formed by the meeting of two faces of a prism;
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base edges: are the straight lines formed by the meeting of one of the bases with a lateral face;
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side edges: are the straight segments formed by the meeting of two lateral faces;
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vertices: are the meeting points between two or more edges;
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diagonals: any line segment that connects two vertices that do not belong to the same face of the prism;
- cross section: is the intersection of the prism with some plane parallel to the bases.
classification of a prism
There are some possible classifications for the prisms. One of them takes into account the number of sides of your bases, which are congruent.
- One prism whose bases are triangles is called triangular prism.
- One prism whose bases are quadrilaterals is called square prism.
- One prism whose bases are pentagons is called pentagonal prism.
And so follows the classification based on the number of sides of the prism bases.
Another classification takes into account the angle between the side edges and the bases:
One prism whose side edges are perpendicular the planes containing its bases are called a straight prism. Otherwise, the prism is called oblique.
Note that the side faces of a prism straight are rectangles. The lateral faces of an oblique prism are parallelograms.
One prism straight line whose bases are regular polygons is called a regular prism.
On the left, a straight prism; on the right, an oblique prism.
cobblestones
You cobblestones they are prisms whose bases are parallelograms. The parallelepiped receives the name of straight parallelepiped or rectangular block when its bases are rectangular. If the six faces of a parallelepiped are square, it will be called a cube.
By Luiz Paulo Moreira
Graduated in Mathematics
Source: Brazil School - https://brasilescola.uol.com.br/o-que-e/matematica/o-que-prisma.htm