"A large nail or pin, generally of iron. The larger forms of spikes, particularly railroad spikes, are…

Illustration of a how to construct a square equivalent to the sum of two given squares.

Illustration of a how to construct a square equivalent to the difference of two given squares.

Illustration used to show how "to construct a tangent to a circle from a point outside."

Pattern that can be cut out and folded to construct a regular tetrahedron. Fold on the dotted lines,…

Illustration showing ambiguous case when the solution is not a triangle using law of sines.

Triangle construction when given two angles and the included side.

Projections and development of a truncated cylinder.