point of tangency
51Apollonius of Perga — Apollonius of Perga. Apollonius of Perga [Pergaeus] (Ancient Greek: Ἀπολλώνιος) (ca. 262 BC – ca. 190 BC) was a Greek geometer and astronomer noted for his writings on conic sections. His innovative methodology and terminology, especially in the… …
52Analytic geometry — Cartesian coordinates. Analytic geometry, or analytical geometry has two different meanings in mathematics. The modern and advanced meaning refers to the geometry of analytic varieties. This article focuses on the classical and elementary meaning …
53Malfatti circles — In geometry, the Malfatti circles are three circles inside a given triangle such that each circle is tangent to the other two and to two sides of the triangle. They are named after Gian Francesco Malfatti, who made early studies of the problem of …
54Tusi-couple — The Tusi couple is a mathematical device in which a small circle rotates inside a larger circle twice the radius of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth… …
55Villarceau circles — In geometry, Villarceau circles (pronEng|viːlɑrˈsoʊ) are a pair of circles produced by cutting a torus diagonally through the center at the correct angle. Given an arbitrary point on a torus, four circles can be drawn through it. One is in the… …
56Soddy's hexlet — [ ellipse.] In geometry, Soddy s hexlet is a chain of six spheres (shown in grey in Figure 1), each of which is tangent to both of its neighbors and also to three mutually tangent given spheres. In Figure 1, these three spheres are shown as an… …
57tractrix — noun The curve that satisfies the following property: That segment of the tangent line that lies between the point of tangency and a fixed line has length independent of the point of tangency chosen …
58tangent — [tan′jənt] adj. [L tangens, prp. of tangere, to touch: see TACT] 1. that touches; touching 2. Geom. touching and not intersecting a curve or curved surface at one and only one point: said of a line or plane n. [< ModL ( linea) tangens, tangent …
59List of gear nomenclature — Gears have a wide range of unique terminology known as gear nomenclature. Many of the terms defined cite the same reference work.[1] Contents 1 Addendum 2 Addendum angle 3 Addendum circle …
60Atomic orbital — The shapes of the first five atomic orbitals: 1s, 2s, 2px, 2py, and 2pz. The colors show the wave function phase. These are graphs of ψ(x,y,z) functions which depend on the coordinates of one electron. To see the elongated shape of ψ(x,y,z)2… …
