TRIGGEOM

This site is to be devoted to the various aspects of the triangle geometry.

My other (main) site is here.

1. Non-trivial dissection of 3-4-5 Triangle to four triangles with equal area
2. Dissection of 3-4-5 Triangle to two triangles with equal incircles
3. Dissection of arbitrary triangle to two triangles with equal incircles
4. Find this segment!
5. Find this point!
6. Non-trivial dissection of Regular Triangle to four triangles with equal area
7. Non-trivial dissection of Arbitrary Triangle to four triangles with equal area
8. Centroid and 3-points of the 3-4-5 Triangle
9. Area covered by 3-points in the triangle
10. Bi-bisector triangle in the 3-4-5 triangle
11. Three isosceles triangles
12. Locus of iso-angle points in the 3-4-5 triangle
13. Right triangle with known inradius and altitude
14. Right triangle with known inradius and altitude-2
15. Do these three segments meet? No!
16. How to dissect the triangle to combine the square?
17. Five similar triangles
18. Cut the 3-4-5 Triangle and make the Square!
19. Find the Cosine of the 'alpha'!
    
20. The Altitude-Bisector-Median Concurrence:
    1. In the right-angled triangle
    2. In the arbitrary triangle
21. Find the sides of the triangle!
22. Find this area!
23. Euler Line Parallel To Side
24. The Nice Letter A
25. Find the area of the triangle!
26. Triangle as a word
27. TRIANGLE as an ANAGRAM
28. Triangle with perimeter and angles
29. The small leg of the integral right triangle
30. Two center traces
31. PointAngleProblem - 1 (PAP1)
32. PointAngleProblem - 2 (PAP2)
33. PointAngleProblem - 3 (PAP3)
34. PointAngleProblem - 4 (PAP4)
35. PointAngleProblem - 5 (PAP5)
36. PointAngleProblem - 6 (PAP6)
37. PointAngleProblem - 7 (PAP7)
38. PointAngleProblem - 8 (PAP8)
39. PointAngleProblem - 9 (PAP9)
40. PointAngleProblem - 10 (PAP10)
41. Find the mean chevian to hypotenuse!
42. Find the mean chevian to larger leg !
43. Find the mean chevian to lesser leg!
44. Find the area of inner triangles!
45. Find the area of inner triangles-2
46. TriangleInCircle Problem - 1 (TIC1)
47. TriangleInCircle Problem - 2 (TIC2)
48. RegularReflectionTriangle Problem
49. Find the circle center!
50. Three Angular Bisectors Problem
51. Three Angular Bisectors Problem - 2
52. Four Angular Bisectors Problem
53. Four Angular Bisectors Problem - 2
54. Five Angular Bisectors Problem
55. Three Distances_Problem
56. Find the angles of the right triangle ABC!
57. Sum of tangents of angles of triangle ABC
58. Three equal area triangles: 3-4-5 triangle case
59. Two chevians make triangle in the right triangle
60. Is it a right triangle?
61. Inspired by problem 726.
62. Area of the triangle HBC.
63. Making triangle from chevians.
64. "Generalization" of the Pythagorean Theorem?
65. Rectangle-to-4-similar-triangles puzzle
66. Cut square to similar unequal triangles!
67. Cut square to three similar unequal rectangles!
68. Cut square to 8 similar unequal triangles
69. Cut rectangle to 2 similar unequal rectangles
70. Parallel lines
71. Heights' Spiral
72. Inside Points
73. Mean perimeter of triangle inscribed in 3-4-5 triangle
74. Triangle DEF inscribed in 3-4-5 triangle
75. Two smallest Pythagorean triangles

    more coming soon...

Some other (great) sites:

• Miriam-Webster Dictionary
• Cambridge Dictionaries Online
• PROMT's Online Translator
• SYSTRAN Online Translator
• Eric Weisstein's World of Mathematics
• On-Line Encyclopedia of Integer Sequences
• Clark Kimberling's Encyclopedia of Triangle Centers - ETC
• Alexander Bogomolny's Cut-The-Knot Site
• Arkadii Slinko's Math Olimpiad Site
• Jim Wilson Home Page
• geometry-puzzles group

And the last (but not the least) question:
What does this number mean on earth?





Answer (not solution!) is here