Two intersecting planes on a third plane. "If two intersecting planes are each perpendicular to a third…

Illustration of two parallel planes. "Two planes perpendicular to the same straight line are parallel."

Two parallel planes perpendicular to a line (AB). "A straight line perpendicular to one of two parallel…

"If two intersecting lines are each parallel to a given plane, the plane of these lines is parallel…

"If two planes are perpendicular to each other, a line in one of them perpendicular to the intersection…

"The glass roof is commonly designed so as to form a uniform plane or slope from back to front in lean-to…

Draw the plan and elevation of a polygon of which the real shape and position in a given plane are known.

Illustration of a prism - a polyhedron of which two faces are equal polygons in parallel planes, and…

"A proof-plane may be made by cementing a bronze cent or a disk of gilt paper to a thin insulating handle,…

"If a pyramid be cut by a plane, parallel to the base, so as to form two parts, the lower part is called…

"A screw is a cylinder with a helical proection winding around its circumference. This helix is called…

"A ratchet brace is a powerful instrument, and carries in itself the screw for obtaining the requisite…

"From the surface of a plane mirror, parallel rays are reflected parallel; but the convex mirror causes…

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…

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 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.…

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.

"Plane mirrors M revolve on an endless chain placed outside of the apparatus and alter the direction…

"A series of planes as S—S are passed perpendicular to the axis of revolution, cutting out the…

Illustration showing a section of the rolling surfaces by a plane perpendicular to their straight line…

A propeller airplane with rudder, elevator, and ailerons. The rudder stabilizes the plane vertical,…

"That the screw is a modified inclined plane, may be shown by winding a triangular piece of paper around…

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…

Illustration of two intersecting spheres. "The intersection of two spherical surfaces is the circumference…

In this illustration, "the driven surface of the slide coincides with the tangent to the spiral, the…

Illustration of the intersection of a square pyramid and a plane.

Illustration of the intersection of a square pyramid and a plane.

"The wood-worker's main stand-by for boring is the stock or brace and set of bits." — Encyclopedia…

An early invention of the airplane, created by John Stringfellow in the mid-19th century.

Illustration of the intersection of a triangular pyramid and a plane.

The desire to reproduce in wood these old stone ornaments led to the invention of a great number of…

The desire to reproduce in wood these old stone ornaments led to the invention of a great number of…

"The next simple mechanical power is the wedge. This instrument may be considered as two inclined planes,…

"A wedge is a triangular prism of hard material, fitted to be driven between objects that are to be…

"[A wedge] is simply a movable inclined plane, or two such planes united a their bases." -Avery 1895

"The wedge is a movable inclined plane, and is used for moving a great weight a short distance. A common…

"This wedge is a movable inclined plane. Allows for raising great weights a short distance." —Quackenbos…