Search results
Results from the WOW.Com Content Network
A pyramid is a polyhedron that may be formed by connecting a polygonal base and a point, called the apex. Each base edge and apex form an isosceles triangle, called a lateral face. [7] The edges connected from the polygonal base's vertices to the apex are called lateral edges. [8] Historically, the definition of a pyramid has been described by ...
The tetrahedron is one kind of pyramid, which is a polyhedron with a flat polygon base and triangular faces connecting the base to a common point. In the case of a tetrahedron, the base is a triangle (any of the four faces can be considered the base), so a tetrahedron is also known as a "triangular pyramid".
Frustum. In geometry, a frustum ( Latin for 'morsel'); [ a] ( pl.: frusta or frustums) is the portion of a solid (normally a pyramid or a cone) that lies between two parallel planes cutting the solid. In the case of a pyramid, the base faces are polygonal and the side faces are trapezoidal. A right frustum is a right pyramid or a right cone ...
This lateral surface area can be calculated by multiplying the perimeter of the base by the height of the prism. [2] For a right circular cylinder of radius r and height h, the lateral area is the area of the side surface of the cylinder: A = 2πrh. For a pyramid, the lateral surface area is the sum of the areas of all of the triangular faces ...
Triangular bipyramid. In geometry, the triangular bipyramid is the hexahedron with six triangular faces, constructed by attaching two tetrahedra face-to-face. The same shape is also called the triangular dipyramid [1] [2] or trigonal bipyramid. [3] If these tetrahedra are regular, all faces of triangular bipyramid are equilateral.
In the case of a triangular prism, its base is a triangle, so its volume can be calculated by multiplying the area of a triangle and the length of the prism: , where b is the length of one side of the triangle, h is the length of an altitude drawn to that side, and l is the distance between the triangular faces. [9]
A pentagonal pyramid has six vertices, ten edges, and six faces. One of its faces is pentagon, a base of the pyramid; five others are triangles. [2] Five of the edges make up the pentagon by connecting its five vertices, and the other five edges are known as the lateral edges of the pyramid, meeting at the sixth vertex called the apex. [3]
Heptahedron. A heptahedron ( pl.: heptahedra) is a polyhedron having seven sides, or faces . A heptahedron can take a large number of different basic forms, or topologies. The most familiar are the hexagonal pyramid and the pentagonal prism. Also notable is the tetrahemihexahedron, which can be seen as a tessellation of the real projective plane.