Steiner-Lehmus theorem — |AE|=|BD|,,alpha=eta,,gamma=delta Rightarrow riangle ABC ext{ is isosceles}The Steiner Lehmus theorem, a theorem in elementary geometry, was formulated by C. L. Lehmus and subsequently proved by Jakob Steiner.: Any triangle with two angle… … Wikipedia
Circle — This article is about the shape and mathematical concept. For other uses, see Circle (disambiguation). Circle illustration showing a radius, a diameter, the centre and the circumference … Wikipedia
Bisection — In geometry, bisection is the division of something into two equal or congruent parts, usually by a line, which is then called a bisector . The most often considered types of bisectors are segment bisectors and angle bisectors .A segment bisector … Wikipedia
Mass point geometry — Mass point geometry, colloquially known as mass points, is a geometry problem solving technique which applies the physical principle of the center of mass to geometry problems involving triangles and intersecting cevians.[1] All problems that can … Wikipedia
Euclidean geometry — A Greek mathematician performing a geometric construction with a compass, from The School of Athens by Raphael. Euclidean geometry is a mathematical system attributed to the Alexandrian Greek mathematician Euclid, which he described in his… … Wikipedia
List of mathematics articles (A) — NOTOC A A Beautiful Mind A Beautiful Mind (book) A Beautiful Mind (film) A Brief History of Time (film) A Course of Pure Mathematics A curious identity involving binomial coefficients A derivation of the discrete Fourier transform A equivalence A … Wikipedia
List of triangle topics — This list of triangle topics includes things related to the geometric shape, either abstractly, as in idealizations studied by geometers, or in triangular arrays such as Pascal s triangle or triangular matrices, or concretely in physical space.… … Wikipedia
Triangle — This article is about the basic geometric shape. For other uses, see Triangle (disambiguation). Isosceles and Acute Triangle redirect here. For the trapezoid, see Isosceles trapezoid. For The Welcome to Paradox episode, see List of Welcome to… … Wikipedia
Problem of Apollonius — In Euclidean plane geometry, Apollonius problem is to construct circles that are tangent to three given circles in a plane (Figure 1); two circles are tangent if they touch at a single point. Apollonius of Perga (ca. 262 BC ndash; ca. 190 BC)… … Wikipedia
Special cases of Apollonius' problem — In Euclidean geometry, Apollonius problem is to construct all the circles that are tangent to three given circles. Limiting cases of Apollonius problem are those in which at least one of the given circles is a point or line, i.e., is a circle of… … Wikipedia