Illustration of a right rectangular pyramid that has been cut by a plane parallel to the base. The lower part is known as the frustum.

Rectangular Pyramid Cut By Plane

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

The illustration of a rectangular pyramid unfolded by creating edges equal length to the base and meeting at point E.

Development of Rectangular Pyramid

The illustration of a rectangular pyramid unfolded by creating edges equal length to the base and meeting…

Illustration of a right rectangular pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Rectangular Pyramid

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 section has been removed and the remaining section is known as the frustum of the pyramid.

Frustum Of A Rectangular Pyramid

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

Illustration of a right hollow rectangular pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section has been turned upside down. It is known as the frustum of the pyramid.

Frustum Of A Rectangular Pyramid

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

Illustration of a right hollow rectangular pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section has been turned upside down. It is known as the frustum of the pyramid. Hidden edges are shown in this drawing.

Frustum Of A Rectangular Pyramid

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

Illustration of a frustum of a pyramid having a rectangular base and a hole passing through the center of the frustum.

Frustum Of A Rectangular Pyramid With Hole

Illustration of a frustum of a pyramid having a rectangular base and a hole passing through the center…

Popcorn box that is in the shape of a frustum of a rectangular pyramid.

Popcorn Box Frustum Of A Rectangular Pyramid

Popcorn box that is in the shape of a frustum of a rectangular pyramid.

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which belongs a number of forms having some property in common. In order to classify these different crystals, the existence of certain lines within the crystal, called axes, is assumed, around which the form can be symmetrically build up. These axes are assumed to intersect in the center of the crystal, and to pass through from one side to the other." — Hallock, 1905

Rhombohedron

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

"Tetragonal. Usually prismatic with pyramid terminations." — Ford, 1912

Rutile

"Tetragonal. Usually prismatic with pyramid terminations." — Ford, 1912

"A crystal of scapolite, upon which the faces of the third-order pyramid are shown." — Ford, 1912

Scapolite

"A crystal of scapolite, upon which the faces of the third-order pyramid are shown." — Ford, 1912

This figure shows a combination of forms sometimes observed on the silicate Scapolite, with the unit pyramid, (o); the prisms of the first and second orders, (M) and (b) respectively; and the pyramid of the third order, (s).

Scapolite

This figure shows a combination of forms sometimes observed on the silicate Scapolite, with the unit…

"This is a form composed of twelve isoceles triangular faces, each of which intersects two of the horizontal axes equally, the third and immediate horizontal axis at one-half this distance, and also intersects the vertical axis." — Ford, 1912

Pyramid of the second order

"This is a form composed of twelve isoceles triangular faces, each of which intersects two of the horizontal…

Illustration of a right septagonal/heptagonal pyramid, with hidden edges shown, that has been cut by a plane parallel to the base. The lower part is known as the frustum.

Septagonal/Heptagonal Pyramid Cut By Plane

Illustration of a right septagonal/heptagonal pyramid, with hidden edges shown, that has been cut by…

Illustration of a septagonal/heptagonal pyramid that has been cut by a plane parallel to the base. The top section has been removed and the remaining section is known as the frustum of the pyramid. The hidden edges are shown in this illustration.

Frustum Of A Septagonal/Heptagonal Pyramid

Illustration of a septagonal/heptagonal pyramid that has been cut by a plane parallel to the base. The…

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which belongs a number of forms having some property in common. In order to classify these different crystals, the existence of certain lines within the crystal, called axes, is assumed, around which the form can be symmetrically build up. These axes are assumed to intersect in the center of the crystal, and to pass through from one side to the other." — Hallock, 1905

Six-sided Pyramid

"Science has succeeded in classifying the thousands of known crystals in six systems, to each of which…

Illustration of a sphere inscribed in a tetrahedron.

Sphere Inscribed in Tetrahedron

Illustration of a sphere inscribed in a tetrahedron.

Illustration of a sphere inscribed in a tetrahedron.

Sphere Inscribed in Tetrahedron

Illustration of a sphere inscribed in a tetrahedron.

Illustration showing that "the solids formed by the dissected part of the sphere are pyramids."

Sphere Formed By Pyramids

Illustration showing that "the solids formed by the dissected part of the sphere are pyramids."

The Chaldaean Temple viewed from the sky.

Chaldaean Temple

The Chaldaean Temple viewed from the sky.

This illustration shows the union of a pyramid and a prism of different orders.

Union of a Pyramid and a Prism of Different Orders

This illustration shows the union of a pyramid and a prism of different orders.

This illustration shows the union of a pyramid and a prism of the same order.

Union of a Pyramid and a Prism of the Same Order

This illustration shows the union of a pyramid and a prism of the same order.

This form shows a very complex combination of thirteen tetragonal forms occuring on the mineral Vesuvianite: the prism of the first order, (d); prism of the second order, (M); basal pinacoid, (s); three pyramids of the first order, (c), (b), and (u); the ditetragonal prism (f); and the four ditetragonal pyramids (z), (x), (e), and (a).

Vesuvianite

This form shows a very complex combination of thirteen tetragonal forms occuring on the mineral Vesuvianite:…

Also known as Fergusonite, this crystal shows the basal pinacoid, (c); the unit pyramid, (s); and the pyramid and prism of the third order, (z) and (r) respectively.

Yttrium Niobate

Also known as Fergusonite, this crystal shows the basal pinacoid, (c); the unit pyramid, (s); and the…

"A crystal of zincite with a prism terminated by a pyramid above a basal pinacoid below." — Ford, 1912

Zincite

"A crystal of zincite with a prism terminated by a pyramid above a basal pinacoid below." — Ford,…