"A pyramid is a solid whose base is a polygon, and whose sides are triangles uniting at a common point,…

Illustration used to compare the volumes of a pyramid and a prism by emptying sand from the pyramid…

"a shows a young tree with its second year's growth, the upright shoot of the maiden tree having been…

"The pyramids of Egypt are well entitled to a place among the most interesting curiosities in the world.…

A sample exercise problem to complete the top part and create a stretched out image of the oblique hexagonal…

The problem exercise in completing the top view and creating the development, or rolled out, image of…

"The dihexagonal pyramid is a form of twenty-four isoceles triangular faces, each of which intersects…

"The ditetragonal pyramid is a form composed of sixteen isoceles trianglular faces, each of which intersects…

"The pyramid of the first order is a form consisting of eight isoceles triangular faces, each of which…

The frustum of a pyramid is the portion of a pyramid included between the base and a section parallel…

The volume of the frustum of any pyramid is equal to the sum of the volumes of three pyramids whose…

An illustration of a pyramid with the top cut off by a plane parallel to the base. The remaining part…

Illustration of a regular pyramid with a pentagon for a base.

The frustum of a pentagonal pyramid is the portion of a pyramid included between the base and a section…

Illustration of a right hexagonal pyramid with hidden edges shown. The base is a hexagon and the faces…

Illustration of a right hexagonal pyramid with hidden edges shown. The base is a hexagon and the faces…

Illustration of a hollow right hexagonal pyramid. The base is a hexagon and the faces are isosceles…

Illustration of a hollow right nonagonal pyramid. The base is a nonagon and the faces are isosceles…

Illustration of a hollow right octagonal pyramid. The base is an octagon and the faces are isosceles…

Illustration of a hollow right rectangular pyramid. The base is a rectangle and the faces are isosceles…

Illustration of a hollow right heptagonal (septagonal) pyramid. The base is a heptagon and the faces…

Illustration of a hollow right heptagonal (septagonal) pyramid. The base is a heptagon and the faces…

Illustration of a right nonagonal pyramid with hidden edges shown. The base is a nonagon and the faces…

Illustration of a right octagonal pyramid with hidden edges shown. The base is an octagon and the faces…

Illustration of a right pentagonal pyramid with hidden edges shown. The base is an pentagon and the…

Illustration of a right pentagonal pyramid with hidden edges shown. The base is an pentagon and the…

Illustration of a right pentagonal pyramid viewed from below with hidden edges shown. The base is an…

Illustration of a right pentagonal pyramid viewed from below. The base is an pentagon and the faces…

Illustration of pentagonal pyramid used to show that the volume is equal to one third of the product…

Illustration of a right rectangular pyramid with hidden edges shown. The base is a rectangle and the…

Illustration of a right rectangular pyramid with hidden edges shown. The base is a rectangle and the…

Illustration of a right rectangular pyramid with hidden edges shown. The base is a rectangle and the…

"The pyramid of the second order is a form composed of eight isoceles triangular faces, each of which…

Illustration of a right septagonal/heptagonal pyramid with hidden edges shown. The base is a heptagon…

Illustration of a non-right, or skewed, hexagonal pyramid with hidden edges shown. The base is a hexagon…

Illustration of a non-right, or skewed, rectangular pyramid with hidden edges shown. The base is a rectangle…

Illustration of triangular pyramid used to show that the volume is the limit of the sum of the volumes…

Illustration of triangular pyramid used to show that the volume is equal to one third of the product…

An illustration of two pyramids. A pyramid is a building where the upper surfaces are triangular and…

Illustration of 2 right pentagonal pyramids with hidden edges shown. The pentagonal bases are congruent,…

Illustration of 2 right rectangular pyramids with hidden edges shown. The rectangular bases are congruent,…

Two triangular pyramids having equivalent bases and equal altitudes are equivalent.

Illustration of pentagonal and triangular pyramids cut by a plane parallel to the bases.

Illustration of 2 similar right pentagonal pyramids with hidden edges shown. The height of the pyramid…

Illustration showing that the volume of 2 triangular pyramids, having the same trihedral angle of the…

"Terminated usually by a combination of a positive and negative rhombohedron, which often are so equally…

Illustration of a right rectangular pyramid that has been cut by a plane parallel to the base. The lower…

Illustration of a right rectangular pyramid that has been cut by a plane parallel to the base. The top…

Illustration of a right rectangular pyramid that has been cut by a plane parallel to the base. The top…