Ví dụ về việc sử dụng The reuleaux triangle trong Tiếng anh và bản dịch của chúng sang Tiếng việt
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The Reuleaux triangle has also been used in other styles of architecture.
Respectively; the sum of these radii equals the width of the Reuleaux triangle.
By Barbier's theorem allcurves of the same constant width including the Reuleaux triangle have equal perimeters.
Similar maps also based on the Reuleaux triangle were published by Oronce Finé in 1551 and by John Dee in 1580.[1].
Circular triangles are triangles with circular-arc edges, including the Reuleaux triangle as well as other shapes.
The Reuleaux triangle can be generalized to regular polygons with an odd number of sides, yielding a Reuleaux polygon.
Several types of machinery take the shape of the Reuleaux triangle, based on its property of being able to rotate within a square.
The Reuleaux triangle may be constructed either directly from three circles, or by rounding the sides of an equilateral triangle.[6].
Its four vertices lie at the three corners andone of the side midpoints of the Reuleaux triangle(above to the right).[6].
Although the Reuleaux triangle has sixfold dihedral symmetry,the same as an equilateral triangle, it does not have central symmetry.
Because of this property of rotating within a square, the Reuleaux triangle is also sometimes known as the Reuleaux rotor.[1].
Panasonic's RULO roboticvacuum cleaner has its shape based on the Reuleaux triangle in order to ease cleaning up dust in the corners of rooms.[34][35].
The Reuleaux triangle can also be generalized into three dimensions in multiple ways:the Reuleaux tetrahedron(the intersection of four balls whose centers lie on a regular tetrahedron) does not have constant width, but can be modified by rounding its edges to form the Meissner tetrahedron, which does.
Among constant-width shapes with a given width, the Reuleaux triangle has the minimum area and the sharpest(smallest) possible angle(120°) at its corners.
The Reuleaux triangle may also be interpreted as the conformal image of a spherical triangle with 120° angles.[1] This spherical triangle is one of the Schwarz triangles(with parameters 3/2, 3/2, 3/2), triangles bounded by great-circle arcs on the surface of a sphere that can tile the sphere by reflection.
In its use in Gothic church architecture,the three-cornered shape of the Reuleaux triangle may be seen both as a symbol of the Trinity,[50] and as"an act of opposition to the form of the circle".
The Reuleaux triangle is the least symmetric curve of constant width according to two different measures of central asymmetry, the Kovner- Besicovitch measure(ratio of area to the largest centrally symmetric shape enclosed by the curve) and the Estermann measure(ratio of area to the smallest centrally symmetric shape enclosing the curve).
By the Blaschke- Lebesgue theorem, the Reuleaux triangle has the smallest possible area of any curve of given constant width. This area is.
However, the Reuleaux triangle is the rotor with the minimum possible area.[1] As it rotates, its axis does not stay fixed at a single point, but instead follows a curve formed by the pieces of four ellipses.[28] Because of its 120° angles, the rotating Reuleaux triangle cannot reach some points near the sharper angles at the square's vertices, but rather covers a shape with slightly rounded corners, also formed by elliptical arcs.[9].
Reuleaux's original motivation for studying the Reuleaux triangle was as a counterexample, showing that three single-point contacts may not be enough to fix a planar object into a single position.
For the Reuleaux triangle, the two centrally symmetric shapes that determine the measures of asymmetry are both hexagonal, although the inner one has curved sides.[17] The Reuleaux triangle has diameters that split its area more unevenly than any other curve of constant width. That is, the maximum ratio of areas on either side of a diameter, another measure of asymmetry, is bigger for the Reuleaux triangle than for other curves of constant width.[18].
Many guitar picks employ the Reuleaux triangle, as its shape combines a sharp point to provide strong articulation, with a wide tip to produce a warm timbre.
Because all its diameters are the same, the Reuleaux triangle is one answer to the question"Other than a circle, what shape can a manhole cover be made so that it cannot fall down through the hole?"[2].
Another class of applications of the Reuleaux triangle involves using it as a part of a mechanical linkage that can convert rotation around a fixed axis into reciprocating motion.[10] These mechanisms were studied by Franz Reuleaux. .
Another early application of the Reuleaux triangle, Leonardo da Vinci's world map, by Leonardo da Vinci circa 1514(or possibly by one of his followers at his direction), was a world map in which the spherical surface of the earth was divided into eight octants, each flattened into the shape of a Reuleaux triangle.[53][54][55].
In connection with the inscribed square problem, Eggleston(1958) observed that the Reuleaux triangle provides an example of a constant-width shape in which no regular polygon with more than four sides can be inscribed, except the regular hexagon, and he described a small modification to this shape that preserves its constant width but also prevents regular hexagons from being inscribed in it.
To construct a Reuleaux triangle.