Roulette curve made from circles with radii that differ by factors of 3 or 1.5
Fixed outer circle
Rolling circle (1/3 the radius of the outer circle)
Deltoid curve formed by tracing a circumferential point on the rolling circle
In geometry, a deltoid curve, also known as a tricuspoid curve or Steiner curve, is a hypocycloid of three cusps. In other words, it is the roulette created by a point on the circumference of a circle as it rolls without slipping along the inside of a circle with three or one-and-a-half times its radius. It is named after the capital Greek letter delta (Δ) which it resembles.
More broadly, a deltoid can refer to any closed figure with three vertices connected by curves that are concave to the exterior, making the interior points a non-convex set.[1]
^"Area bisectors of a triangle". www.se16.info. Retrieved 26 October 2017.
In geometry, a deltoidcurve, also known as a tricuspoid curve or Steiner curve, is a hypocycloid of three cusps. In other words, it is the roulette created...
of quadrilateral A deltoidcurve, a three-cusped hypocycloid A leaf shape The deltoid tuberosity, a part of the humerus The deltoid ligament, a ligament...
superellipse with n = 2⁄3 and a = b, is a hypocycloid with four cusps. Deltoidcurve, the hypocycloid of three cusps. Squircle, the superellipse with n = 4...
properties for this construction is the deltoidcurve, and the involutes of the deltoid that enclose it form smooth curves of constant width, not containing...
triangle as well as other shapes. The deltoidcurve is another type of curvilinear triangle, but one in which the curves replacing each side of an equilateral...
In algebraic geometry, a quartic plane curve is a plane algebraic curve of the fourth degree. It can be defined by a bivariate quartic equation: A x 4...
The deltoid tubercle of spine of scapula is a prominence on the spine of scapula. The spine, at lateral to the root of the spine, curves down and laterally...
kind of roulette. A hypocycloid with three cusps is known as a deltoid. A hypocycloid curve with four cusps is known as an astroid. The hypocycloid with...
curve of a given curve results from the orthogonal projection of a fixed point on the tangent lines of this curve. More precisely, for a plane curve C...
In the differential geometry of curves, the evolute of a curve is the locus of all its centers of curvature. That is to say that when the center of curvature...
gearing Straight-line mechanism Spirograph Geometric lathe Guilloché Deltoidcurve Wikimedia Commons has media related to Tusi-couple. Roshdi Rashed (ed...
this surface is a rough, rectangular elevation, the deltoid tuberosity for the insertion of the deltoid muscle; below this is the radial sulcus, directed...
on lifting-body development (The Deltoid Pumpkin Seed), the psyche and experience of a nuclear engineer (The Curve of Binding Energy), a New Jersey wilderness...
surfaces. the anterior border is concave forward and gives origin to the deltoid muscle. the posterior border is convex and gives attachment to the trapezius...
now also considered a deltoid and is commonly referred to as the clavodeltoid. The acromiodeltoid is the shortest of the deltoid muscles. It lies lateral...
The shape of the curve at the bottom of a cylindrical cup is half of a nephroid, which looks quite similar. Limaçon Nephroid Deltoid Wittgenstein's rod...
leaves. The leaves of H. fasciata are also often stouter and more deltoid. They tend to curve inwards more. Unlike H. attenuata, older H. fasciata specimens...
the primary muscles involved being the pectoralis major, the anterior deltoids, and the triceps brachii. Other muscles located in the back, legs and core...
pseudotriangulations of a point set in a small amount of time per pseudotriangulation. Deltoidcurve Circular triangle For "pseudo-triangle" see, e.g., Whitehead, J. H....
resembles the capital letter D D-ring Deltoid, the shape that resembles the Greek capital letter Δ Deltahedron Deltoid muscle River delta Delta wing E-shape...
– an epicycloid with two cusps Deltoid – a hypocycloid with three cusps Stoner–Wohlfarth astroid – a use of this curve in magnetics Spirograph Yates J...
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