 |
Apollonius'
Tangency Problem for Three Circles
Illustration with animation and sound.
|
|
|
Archimedes'
Book of Lemmas:Try to solve the Archimedes'
problems of geometry (High school Level) |
|
|
The Archimedes Palimpsest |
|
|
Arbelos,
Inscribed Circle and Concyclic Points |
|
|
Archimedes: 3.14159 is Close Enough |
|
|
Archimedes Index |
|
|
Blanchet Theorem
|
|
|
Brahmagupta's Theorem
Cyclic quadrilateral.
|
|
|
Butterfly Theorem
Proof.
Puzzle. |
|
|
Butterfly Theorem
Introduction. |
|
|
Carnot's Theorem |
|
|
Casey' s Theorem |
|
|
Ceva's Theorem
Concurrency |
|
|
Circles
|
|
|
Clifford's Circle Chain
Theorems |
|
|
Crop Circles
and Complexity |
|
|
Einstein
and Pythagoras theorem proof
|
|
|
Equilic
Quadrilateral
Five theorems. |
|
|
Equal Incircles Theorem.
Interactive presentation.
|
|
|
Euclid's
Book I, 23 Definitions |
|
|
Euclid's Elements,
Book XIII, Proposition 10 |
|
|
Eyeball Theorem |
|
|
Fagnano's Problem
|
|
|
Feuerbach
Theorem |
|
|
Interactive Feuerbach Points and Nine-Point Circle |
|
|
Geometry Expressions |
|
|
Geometry, table of
contents |
|
|
Gergonne Point
Theorem |
|
|
De Gua's Theorem |
|
|
Johnson Theorem |
|
|
Heron's
Formula.
Key facts and
a purely geometric
step-by-step proof |
|
|
Isogonic-Jacobi Theorem
TracenPoche |
|
|
Kurschak's Tile
and Theorem |
|
|
Langley Theorem.
Adventitious angles. |
|
|
Lemoine Theorem
|
|
|
Lunes
of Hippocrates 1,
2
, 3,
4
|
|
|
Mascheroni Construction with
compass alone. |
|
|
Marion Walter's Theorem
TracenPoche |
|
|
Menelaus'
Theorem. Triangle and
transversal line. |
|
|
Miquel's Pentagram Theorem
Proof |
|
|
Miquel's
Pentagram Dynamic Geometry |
|
|
Monge &
d'Alembert Three Circles Theorem I
Dynamic
Geometry |
|
|
Monge &
d'Alembert Three Circles Theorem II
Dynamic
Geometry |
|
|
Morley's Theorem |
|
|
Morley's Triangle & Center
TracenPoche |
|
|
Nagel Point Theorem
Proof |
|
|
Napoleon's Theorem |
|
|
Newton's
Theorem |
|
|
Newton's
Theorem, Newton-Gauss Line |
|
|
Nine-Point Center,
Nine-Point Circle, Euler Line |
|
|
Interactive Orthopole
of a Triangle
TracenPoche |
|
|
Parallelogram&Squares |
|
|
Pascal's Mystic Hexagram
Theorem Proof |
|
|
Pentagons and Pentagrams.
Menelaus and Collinearity. |
|
|
Platonic Solids
Interactive animation
|
|
|
Poncelet's Theorem |
|
|
Proposed
Problems about congruence of
line segments, angles, and triangles.
Key Theorems or Facts to know
|
|
|
Proposed
Problem 29,
Geometry Help:
Facts you should know
|
|
|
Proposed
Problem 39.
|
|
|
Proposed
Problem 39 Geometry Help.
|
|
|
Ptolemy's Theorem. |
|
|
Pythagoras Right
Triangles, Formulas and Facts
|
|
|
Pythagoras and Circle Area |
|
|
Cyclic
Quadrilateral: Ratio of the Diagonals
|
|
|
Quadrilaterals Table of
Content |
|
|
Sangaku Theorem
1: Three circles and a tangent line |
|
|
Sangaku
Theorem 2: Cyclic Quadrilateral |
|
|
Sangaku
Problem (An Old Japanese Theorem) |
|
|
Sangaku Problem 41.
"Mickey Mouse." |
|
|
Sawayama -Thebault's
theorem |
|
|
Semiperimeter and Incircle |
|
|
Semiperimeter and
Excircles |
|
|
Semiperimeter, Incircle
and Excircles |
|
|
Seven Circles Theorem
|
|
|
Simson Line |
|
|
Simson Line: Angle |
|
|
Steiner's Theorem |
|
|
Stewart's Theorem |
|
|
100° Isosceles |
|
|
Tessellations Index |
|
|
Three Circles
Theorem
TracenPoche |
|
|
Three
Tangent Circles
Theorem
TracenPoche |
|
|
Triangles
|
|
|
Triangles and
Lissajous Art |
|
|
Triangle with the bisectors of the exterior angles.
Collinearity. |
|
|
Triangle and Squares. 19
theorems, visual illustrations. |
|
|
Triangle and Squares 18
Sangaku Problem |
|
|
Triangle and Squares 19 |
|
|
Triangle&Squares 0
Two squares |
|
|
Triangle&Squares 1
Two squares |
|
|
Triangle&Squares 2
Two squares |
|
|
Triangle&Squares 3
Three squares |
|
|
Triangle with Squares 4
Finsler-Hadwiger Theorem |
|
|
Triangle with Squares
5: Median and Altitude |
|
|
Triangle
with Squares 6: Four squares |
|
|
Triangle Centers |
|
|
Van Aubel's Theorem |
|
|
Adjacent Angles |
|
|
Varignon & Wittenbauer |
