Euclidean geometry | Articles containing proofs | Theorems about triangles
In geometry, Apollonius's theorem is a theorem relating the length of a median of a triangle to the lengths of its sides. It states that "the sum of the squares of any two sides of any triangle equals twice the square on half the third side, together with twice the square on the median bisecting the third side". Specifically, in any triangle if is a median, then It is a special case of Stewart's theorem. For an isosceles triangle with the median is perpendicular to and the theorem reduces to the Pythagorean theorem for triangle (or triangle ). From the fact that the diagonals of a parallelogram bisect each other, the theorem is equivalent to the parallelogram law. The theorem is named for the ancient Greek mathematician Apollonius of Perga. (Wikipedia).
Apollonius' circle construction problems | Famous Math Problems 3 | NJ Wildberger
Around 200 B.C., Apollonius of Perga, the greatest geometer of all time, gave a series of related problems; how to construct a circle in the plane touching three objects, where the objects are either a point (P), a line (L) and or a circle (C). Many mathematicians have studied this most fa
From playlist Famous Math Problems
A Beautiful Proof of Ptolemy's Theorem.
Ptolemy's Theorem seems more esoteric than the Pythagorean Theorem, but it's just as cool. In fact, the Pythagorean Theorem follows directly from it. Ptolemy used this theorem in his astronomical work. Google for the historical details. Thanks to this video for the idea of this visual
From playlist Mathy Videos
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The other famous classical theorem about cyclic quadrilaterals is due to the great Greek astronomer and mathematician, Claudius Ptolemy. Adopting a rational point of view, we need to rethink this theorem to state it in a purely algebraic way, without resort to `distances' and the correspon
From playlist Math Foundations
http://www.teachastronomy.com/ Pythagoras was one of the most influential thinkers in history. This Greek philosopher and mathematician came up with the idea that numbers were the basis of everything. There is no written record, and nothing about Pythagoras survives in writing. He essen
From playlist 02. Ancient Astronomy and Celestial Phenomena
Pythagorean theorem - What is it?
► My Geometry course: https://www.kristakingmath.com/geometry-course Pythagorean theorem is super important in math. You will probably learn about it for the first time in Algebra, but you will literally use it in Algebra, Geometry, Trigonometry, Precalculus, Calculus, and beyond! That’s
From playlist Geometry
APOLLONIUS THEOREM Using Animation Tools | MEDIAN SERIES | CREATA CLASSES
Understand Apollonius Theorem and the Relation between Medians & Sides of a Triangle Using ANIMATION & visual tools. It also include the proof of apollonius theorem. This is 5th video under the Median Series. Introduction to Median: https://youtu.be/eHewPlLq7ps Visit our website: https
From playlist MEDIANS
Pythagorean Theorem V (visual proof; Leonardo da Vinci)
This is a short, animated visual proof of the Pythagorean theorem (the right triangle theorem) using the a diagram that is now attributed to Leonardo da Vinci. The proof uses reflection and rotation symmetry arguments. This theorem states the square of the hypotenuse of a right triangle is
From playlist Pythagorean Theorem
How to Draw Tangent Circles using Cones
Solving the Problem of Apollonius with Conic Sections This video describes a non-standard way of finding tangent circles to a given set of 3 circles, known as the Problem of Apollonius. It uses conic sections rather than straightedge and compass. I feel this approach is more intuitive and
From playlist Summer of Math Exposition Youtube Videos
Tangents to Parametric Curves (New) | Algebraic Calculus One | Wild Egg
Tangents are an essential part of the differential calculus. Here we introduce these important lines which approximate curves at points in an algebraic fashion -- finessing the need for infinite processes to support takings of limits. We begin by a discussion of tangents historically, espe
From playlist Algebraic Calculus One
Pythagoras: A Simple Geometric Proof
Pythagoras' Theorem is one of the most well-remembered, (in)famous things from our time in maths classes, but all too often the proof of it is skipped out 😥 Because the theorem is such a crucial cornerstone of mathematics - and the theorem can be pretty straight-forward to prove - I've de
From playlist Proofs and Explanations
Tangents to Parametric Curves | Algebraic Calculus One | Wild Egg
Tangents are an essential part of the differential calculus. Here we introduce these important lines which approximate curves at points in an algebraic fashion -- finessing the need for infinite processes to support takings of limits. We begin by a discussion of tangents historically, espe
From playlist Algebraic Calculus One from Wild Egg
Ciro Ciliberto, Enumeration in geometry - 15 Novembre 2017
https://www.sns.it/eventi/enumeration-geometry Colloqui della Classe di Scienze Ciro Ciliberto, Università di Roma “Tor Vergata” Enumeration in geometry Abstract: Enumeration of geometric objects verifying some specific properties is an old and venerable subject. In this talk I will
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STPM - Local to Global Phenomena in Deficient Groups - Elena Fuchs
Elena Fuchs Institute for Advanced Study September 21, 2010 For more videos, visit http://video.ias.edu
From playlist Mathematics
Alex Kontorovich - Numbers and Fractals [2017]
It is a very good time to be a mathematician. This millennium, while only a teenager, has already seen spectacular breakthroughs on problems like the Poincar´e Conjecture (solved by Grisha Perelman, who declined both a Fields Medal and a million dollar Clay Prize) and the near-resolution o
From playlist Mathematics
Pythagorean Theorem II (visual proof)
This is a short, animated visual proof of the Pythagorean theorem (the right triangle theorem) using a dissection of a square in two different ways. This theorem states the square of the hypotenuse of a right triangle is equal to the sum of squares of the two other side lengths. #mathshort
From playlist Pythagorean Theorem
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Apollonius introduced the important idea of harmonic conjugates, concerning four points on a line. He showed that the pole polar duality associated with a circle produces a family of such harmonic ranges, one for every line through the pole of a line. Harmonic ranges also occur in the cont
From playlist Universal Hyperbolic Geometry
Converse Pythagorean Theorem & Pythagorean Triples
I explain the Converse Pythagorean Theorem and what Pythagorean Triples are. Find free review test, useful notes and more at http://www.mathplane.com If you'd like to make a donation to support my efforts look for the "Tip the Teacher" button on my channel's homepage www.YouTube.com/Profro
From playlist Geometry
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We continue our discussion of oriented, or signed, or directed circles in the plane, which are also called cycles, and the intimate connection with relativistic geometry in three dimensions. This correspondence makes it easier for us to apply linear algebraic ideas to the geometry of circl
From playlist WildLinAlg: A geometric course in Linear Algebra