Tomahawk (geometric shape)
Encyclopedia
The tomahawk is a "tool" in geometry
consisting of a semicircle and two line segments. The basic shape
is constructible with compass and straightedge
. It is possible to trisect an angle with the tomahawk. This does not contradict the usual theorem stating that an arbitrary angle cannot be trisected
by compass and unmarked straightedge alone, as translating the constructed tomahawk into the required position is not a Euclidean construction
.
Geometry
Geometry arose as the field of knowledge dealing with spatial relationships. Geometry was one of the two fields of pre-modern mathematics, the other being the study of numbers ....
consisting of a semicircle and two line segments. The basic shape
Shape
The shape of an object located in some space is a geometrical description of the part of that space occupied by the object, as determined by its external boundary – abstracting from location and orientation in space, size, and other properties such as colour, content, and material...
is constructible with compass and straightedge
Compass and straightedge
Compass-and-straightedge or ruler-and-compass construction is the construction of lengths, angles, and other geometric figures using only an idealized ruler and compass....
. It is possible to trisect an angle with the tomahawk. This does not contradict the usual theorem stating that an arbitrary angle cannot be trisected
Angle trisection
Angle trisection is a classic problem of compass and straightedge constructions of ancient Greek mathematics. It concerns construction of an angle equal to one-third of a given arbitrary angle, using only two tools: an un-marked straightedge, and a compass....
by compass and unmarked straightedge alone, as translating the constructed tomahawk into the required position is not a Euclidean construction
Euclidean geometry
Euclidean geometry is a mathematical system attributed to the Alexandrian Greek mathematician Euclid, which he described in his textbook on geometry: the Elements. Euclid's method consists in assuming a small set of intuitively appealing axioms, and deducing many other propositions from these...
.
External links
- MathWorld/Wolfram contains other references
- Jim Loy "cheating using other tools"
- Angle Trisection Problem: Trisect An Angle With a Tomahawk at ArticlesForEducators.com