Theorems about circles

Seven circles theorem

In geometry, the seven circles theorem is a theorem about a certain arrangement of seven circles in the Euclidean plane. Specifically, given a chain of six circles all tangent to a seventh circle and each tangent to its two neighbors, the three lines drawn between opposite pairs of the points of tangency on the seventh circle all pass through the same point. Though elementary in nature, this theorem was not discovered until 1974 (by Evelyn, Money-Coutts, and Tyrrell). (Wikipedia).

Seven circles theorem
Video thumbnail

Circles and Solids: Radius, Diameter, and Naming Solids

This video explains how to determine the radius and diameter of a circle. Various solids are also named.

From playlist Circles

Video thumbnail

Grade 6 Module 3 Lesson 5

This video shows how to understand and find the opposite of a number's opposite. Number lines and algorithms are used to show results.

From playlist EngageNY Grade 6 Module 3

Video thumbnail

Using the idea that two tangent lines from a point are equal find the perimeter of a circle

Learn how to solve problems with tangent line. A tangent line to a circle is a line that touches the circle at exactly one point. The tangent line to a circle makes a right angle with the radius of the circle at the point of its tangency. Thus, to solve for any missing value involving the

From playlist Circles

Video thumbnail

Given a circle on a graph learn to write the equation of the circle

Learn how to write the equation of a circle. A circle is a closed shape such that all points are equidistance (equal distance) from a fixed point. The fixed point is called the center of the circle while the distance between any point of the circle and the center of the circle is called th

From playlist Circles

Video thumbnail

Geometry: Ch 3 - Names & Symbols (8 of 8) The Circle

Visit http://ilectureonline.com for more math and science lectures! In this video I will define the names and symbols used in relating a circle. First video in this series can be seen at: https://youtu.be/2fq3RapXeSA

From playlist GEOMETRY 3 - NAMES & SYMBOLS

Video thumbnail

What is the equation for a circle

Learn how to write the equation of a circle. A circle is a closed shape such that all points are equidistance (equal distance) from a fixed point. The fixed point is called the center of the circle while the distance between any point of the circle and the center of the circle is called th

From playlist Circles

Video thumbnail

Area and Perimeter of Geometric Figures

Worked out examples involving area and perimeter.

From playlist Geometry

Video thumbnail

What is the unit circle

👉 Learn about the unit circle. A unit circle is a circle which radius is 1 and is centered at the origin in the cartesian coordinate system. To construct the unit circle we take note of the points where the unit circle intersects the x- and the y- axis. The points of intersection are (1, 0

From playlist Evaluate Trigonometric Functions With The Unit Circle (ALG2)

Video thumbnail

Chords Arcs and Diameters in Circle

I introduce the concept of Chords in a circle and then give you 7 theorems that explain the relationships of chords, arcs, diameters, and central angles is circles. Find free review test, useful notes and more at http://www.mathplane.com If you'd like to make a donation to support my effor

From playlist Geometry

Video thumbnail

The Seven Circles Theorem

This video is based on a paper by Drach and Schwartz. Drach, K., Schwartz, R.E. A Hyperbolic View of the Seven Circles Theorem. Math Intelligencer 42, 61–65 (2020). https://doi.org/10.1007/s00283-019-09952-1 You can read a preprint of the paper here: https://arxiv.org/pdf/1911.00161.pdf

From playlist Summer of Math Exposition 2 videos

Video thumbnail

How to quickly write out the unit circle

👉 Learn about the unit circle. A unit circle is a circle which radius is 1 and is centered at the origin in the cartesian coordinate system. To construct the unit circle we take note of the points where the unit circle intersects the x- and the y- axis. The points of intersection are (1, 0

From playlist Evaluate Trigonometric Functions With The Unit Circle (ALG2)

Video thumbnail

Circles - Geometry

This geometry video tutorial provides a basic introduction into circles. It contains plenty of examples and multiple choice practice problems for you to work on. Here is a list of topics: 1. Inscribed angles in circles and intercepted arcs 2. Radius and chord theorem 3. Diameter and c

From playlist Geometry Video Playlist

Video thumbnail

The Pythagorean Theorem: Extensions and Applications

The Pythagorean Theorem is useful throughout mathematics. This gives just a few examples.

From playlist Lessons of Interest on Assorted Topics

Video thumbnail

Lorenzo Foscolo: ALC manifolds with exceptional holonomy

We will describe the construction of complete non-compact Ricci-flat manifolds of dimension 7 and 8 with holonomy $G_{2}$ and Spin(7) respectively. The examples we consider all have non-maximal volume growth and an asymptotic geometry, so-called ALC geometry, that generalises to higher dim

From playlist Geometry

Video thumbnail

A Pythagorean Theorem for Pentagons + Einstein's Proof

Pythagoras's Theorem is the most famous theorem in mathematics, commonly stated as "the square on the hypotenuse of a right-angled triangle is equal to the sum of the squares on the other two sides." However, Pythagoras's Theorem is not just for squares. In fact it works for any shape.

From playlist My Maths Videos

Video thumbnail

AS/year 12 mathematics - Equation of a Circle & Intersecting Lines (1 of 3: Circles)

00:00 - midpoint formula & perpendicular lines 3:23 - the equation of a circle 7:05 - example questions 12:58 - the distance formula 14:44 - exam style question 18:25 - intersecting straight lines and circles 19:57 - example questions 22:24 - exam style question 28:44 - homework problems

From playlist A-level Mathematics Revision

Video thumbnail

Circles inside right-angle triangles - trigonometry/geometry problems

In this video I go through two trigonometry related problems and one geometry problem I posted last week. These problems also test knowledge of circle theorems and basic properties of shapes. problems from the video - https://bit.ly/39nkj28 ❤️ ❤️ ❤️ Support the channel ❤️ ❤️ ❤️ htt

From playlist Geometry Revision

Video thumbnail

Geometry Final Exam Review - Study Guide

This geometry final exam review contains plenty of multiple choice practice problems as well as some free response questions to help you pass your next test. Here is a list of topics: 1. Right Angles and Angle Addition 2. Segment Addition and Midpoint Theorem 3. Complementary Angles an

From playlist GED Math Playlist

Video thumbnail

How to write the equation of a circle when center is at the origin and radius is given

Learn how to write the equation of a circle. A circle is a closed shape such that all points are equidistance (equal distance) from a fixed point. The fixed point is called the center of the circle while the distance between any point of the circle and the center of the circle is called th

From playlist Circles

Video thumbnail

Advance Information Nov 2022 Predicted Maths GCSE Paper 3 Calculator AQA (Higher) Exam 8300/3H

Do this paper online for free: https://www.onmaths.com/mock_exams/aqa-2022-november-paper-3-higher-prediction/ This is the OnMaths.com predicted paper using the advance information for Nov 2022 AQA Maths GCSE Higher Paper 3 Calculator. The topics within it come from the topics that come

From playlist 2022 November RESIT

Related pages

Brianchon's theorem | Theorem on friends and strangers | Line (geometry) | Point (geometry) | Geometry | Euclidean plane | Circle | Tangent