- triangle
- five squares
- triangle midpoint theorem
- the triangle inequality
- the lunes of Alhazen
- the lune of Hippocrates
- the angle bisector theorems
- classifying triangles...
- triangles...
- triangle angle-sum theorem
- square roots in a greek way...
- pythagorean theorem (a puzzle)
- area of a triangle
- a triangle
- archimedes' arbelos
- areas of similar triangles
- pythagorean theorem (proof)
- equilateral triangle (SAS)
- measuring van gogh's cypress
- the outer Napoleon triangle
- reflections of a triangle
- sierpinski triangles
- triangle-1
- right triangle trigonometry-1
- simson line
- nine-point circle
- angle bisector as locus
- incircle and excircles of a triangle
- an archimedes' formula
- axis of symmetry
- find the tan(φ)
- equal chords
- an isosceles triangle...
- cuboid
- an equilateral triangle
- sum of the interior angles of a n-gon
- a Reuleaux triangle
- congruent triangles
- minimum area (line)
- maximum area (angle)
- area of an equilateral triangle
- generalization (pappus) of pythagorean
- ratio of areas-1
- ratio of areas-2
- an apollonian circle
- law of sines (proof)
- law of cosines (proof)
- Johnson's theorem
- Koch snowflake
- construction of a triangle (sss)
- miquel's triangle theorem
- proof of pythagorean-5
- angle trisection
- first brocard point
- nagel point
- gergonne point
- morley's triangle
- distance between point-line
- vivianni's theorem
- chords and tangents
- the famous "1/7" triangle
- triangles...
- congruent triangles
- right triangle trigonometry
- right triangle trigonometry-2
- chord theorem
- area of a triangle (sas)
- area of a triangle-2
- a square in a square
- lemoine point
- exeter point
- vecten points
- feuerbach's point
- isosceles triangle paradox
- properties of the altitudes
- find the area-1
- triangular numbers
- Solving Similar Triangles (1)
- Water Triangle
- conway circle
- the height of the pyramid
