Proposed Problem
See complete Problem 260 at:
gogeometry.com/problem/p260_equilateral_triangle_incircle_distance_square.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Friday, February 27, 2009
Problem 260: Equilateral Triangle, Incircle, Tangency Points, Vertices, Distances, Square
Thursday, February 26, 2009
Problem 259: Equilateral Triangle, Incircle, Tangency Points, Side, Distances, Squares
Proposed Problem
See complete Problem 259 at:
gogeometry.com/problem/p259_equilateral_triangle_incircle_distance_square.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 258: Equilateral Triangle, Incircle, Point, Vertices, Side, Distances, Squares
Proposed Problem
See complete Problem 258 at:
gogeometry.com/problem/p258_equilateral_triangle_incircle_distance_square.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Tuesday, February 24, 2009
Problem 257: Equilateral Triangle, Circumcircle, Point, Vertices, Side, Distances, Squares
Proposed Problem
See complete Problem 257 at:
gogeometry.com/problem/p257_equilateral_triangle_circumcircle_distance_sides.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 256: Equilateral Triangle, Circumcircle, Point, Vertices, Distances
Proposed Problem
See complete Problem 256 at:
gogeometry.com/problem/p256_equilateral_triangle_circumcircle_distance_vertex.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 255: Triangle, Centroid, Vertices, Interior/Exterior Point, Distances, Squares
Proposed Problem
See complete Problem 255 at:
gogeometry.com/problem/p255_triangle_centroid_squares_point_vertex.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Monday, February 23, 2009
Problem 254: Triangle, Centroid, Vertices, Interior/Exterior Point, Distances, Squares
Proposed Problem
See complete Problem 254 at:
gogeometry.com/problem/p254_triangle_centroid_squares_interior_point.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Pentagon Index
Theorems and Problems
See complete Pentagon Index at:
http://www.gogeometry.com/geometry/pentagon_polygon_shape_index_5_sides.html
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Sunday, February 22, 2009
Problem 253: Triangle, Centroid, Vertices, Distances, Squares
Proposed Problem
See complete Problem 253 at:
gogeometry.com/problem/p253_triangle_centroid_squares.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Equilateral Triangle Index
Theorems and Problems
See complete Equilateral Triangle Index at:
gogeometry.com/geometry/equilateral_triangle_index_equal_sides.html
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Saturday, February 21, 2009
Problem 19: Isosceles Right Triangle, Excenter, Perpendicular, Congruence
Proposed Problem
Try to use elementary geometry (Euclid's Elements)
See complete Problem 19 at:
gogeometry.com/problem/problem019.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 18: Right triangles, Angles, Congruence
Proposed Problem
See complete Problem 18 at:
gogeometry.com/problem/problem018.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 17: Right triangles and Angles
Proposed Problem
See complete Problem 17 at:
gogeometry.com/problem/problem017.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Massacre of the Innocents by Peter Paul Rubens
Golden Rectangle
Peter Paul Rubens (1577 - 1640). Flemish painter, draughtsman and diplomat. He was the most versatile and influential Baroque artist of northern Europe in the 17th century. He is well-known for his Counter-Reformation altarpieces, portraits, landscapes, and history paintings of mythological and allegorical subjects.
At a Sotheby's auction on July 10, 2002, Rubens' newly discovered painting Massacre of the Innocents sold for £49.5million ($76.2 million) to Lord Thomson. It is a current record for an Old Master painting.
Click the figure below to see the interactive illustration of Massacre of the Innocents by Peter Paul Rubens.
Continue reading at:
gogeometry.com/wonder_world/peter_paul_rubens_massacre_innocents_golden.html
New York City by Piet Mondrian
Golden Rectangle
Piet Mondrian was a Dutch painter, a pioneer of Geometric abstraction.
New York City (1941-42) Oil on canvas 119 x 114 cm (46 7/8 x 44 7/8 in) Musee national d'art moderne, Centre Georges Pompidou, Paris. In the further attempt to simplify and perfect his images, he did not use any curved lines or organic shapes, he used only straight lines and geometric shapes. He also only used black, white, gray, and the three primary colors – bright red, blue, and yellow. The use of his simple geometric shapes and basic colors formed a new style or art movement called De Stijl.
Click the figure below to see the interactive illustration of Piet Mondrian, New York City 1941-42.
Continue reading at:
gogeometry.com/wonder_world/piet_mondrian_broadway_boogie_woogie_golden.html
Piet Mondrian, Broadway Boogie Woogie
Golden Rectangle
Piet Mondrian was a Dutch painter, a pioneer of Geometric abstraction.
Broadway Boogie Woogie (1942-1943) Oil on canvas 50 x 50 in. (127 x 127 cm) The Museum of Modern Art, New York. It was his final painting, the checkerboard lines, are painted blue, gray, red and yellow. (The yellow was apparently inspired by New York’s Yellow cabs). In the further attempt to simplify and perfect his images, he did not use any curved lines or organic shapes, he used only straight lines and geometric shapes. He also only used black, white, gray, and the three primary colors – bright red, blue, and yellow. The use of his simple geometric shapes and basic colors formed a new style or art movement called De Stijl.
Click the figure below to see the interactive illustration of Piet Mondrian, Broadway Boogie Woogie.
Continue reading at:
gogeometry.com/wonder_world/piet_mondrian_broadway_boogie_woogie_golden.html
Thursday, February 19, 2009
Paris Review, 1984 by Sol LeWitt and the Golden Rectangle
Golden Rectangle
Sol LeWitt (1928 - 2007) was an American artist linked to various movements, including Conceptual art and Minimalism. LeWitt , whose art is rooted in basic geometry, rose to fame in the late 1960s with his wall drawings and "structures" but was prolific in a wide range of media including drawing, printmaking, and painting.
Click the figure below to see the interactive illustration of Paris Review, 1984 by Sol LeWitt and Golden Rectangle.
Continue reading at:
gogeometry.com/wonder_world/sol_lewitt_paris_review_golden_rectangle.html
The Barolo Chapel or Cappella delle Brunate by Sol LeWitt
Golden Rectangle
Sol LeWitt (1928 - 2007) was an American artist linked to various movements, including Conceptual art and Minimalism. LeWitt , whose art is rooted in basic geometry, rose to fame in the late 1960s with his wall drawings and "structures" but was prolific in a wide range of media including drawing, printmaking, and painting.
Click the figure below to see the interactive illustration of The Barolo Chapel or Cappella delle Brunate by Sol LeWitt and Golden Rectangle.
Continue reading at:
gogeometry.com/wonder_world/sol_lewitt_brunate_golden_rectangle.html
Wednesday, February 18, 2009
Problem 16: Triangle, Cevian, Perpendicular, Angles, Congruence
Proposed Problem
See complete Problem 16 at:
http://gogeometry.com/problem/problem016.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 15: Triangle, Cevian, Angles, Congruence
Proposed Problem
See complete Problem 15 at:
http://gogeometry.com/problem/problem015.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 14: Triangle, Cevian, Midpoint, Angles
Proposed Problem
See complete Problem 14 at:
http://gogeometry.com/problem/problem014.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 13: Triangle, Angles, Congruence, Cevian
Proposed Problem
See complete Problem 13 at:
http://gogeometry.com/problem/problem013.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 12: Triangle, Cevian, Angles, Congruence
Proposed Problem
See complete Problem 12 at:
http://gogeometry.com/problem/problem012.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 11: Right triangle, Cevian, Angles
Proposed Problem
See complete Problem 11 at:
http://gogeometry.com/problem/problem011.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 252. Rectangle, isosceles right triangle, square, areas
Proposed Problem
See complete Problem 252 at:
gogeometry.com/problem/p252_rectangle_triangle_square_area.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Tuesday, February 17, 2009
Theo van Doesburg: Arithmetic Composition. 1929-1930.
Golden Rectangle
Theo van Doesburg (1883 - 1931) was a Dutch artist, practicing in painting, writing, poetry and architecture. He is best known as the founder and leader of De Stijl.
De Stijl, also known as neoplasticism, was a Dutch artistic movement founded in 1917. Proponents of De Stijl sought to express a new utopian ideal of spiritual harmony and order. They advocated pure abstraction and universality by a reduction to the essentials of form and color; they simplified visual compositions to the vertical and horizontal directions, and used only primary colors along with black and white.
Click the figure below to see the interactive illustration of Arithmetic Composition.
Continue reading at:
gogeometry.com/wonder_world/theo_van_doesburg_arithmetic_composition_golden_rectangle.html
Monday, February 16, 2009
Problem 251. Parallelogram, sides, diagonals, squares, areas
Proposed Problem
See complete Problem 251 at:
gogeometry.com/problem/p251_parallelogram_diagonal_square_area.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Sunday, February 15, 2009
Peru's 'The Milk of Sorrow' Takes Berlin Film Festival Top Award 2009
Golden Rectangle
'La Teta Asustada' a Peruvian drama about a young woman with a mysterious illness, won the Golden Bear award for the best movie at the Berlin Film Festival last night. Directed by Claudia Llosa, the film stars Magaly Solier as Fausta, who suffers from a disease she believes is transmitted through the breast milk of women who were raped in the Shining Path's war of terror in Peru. Her life starts to change direction after her mother dies and she goes to live in Lima.
Click the figure below to see the interactive illustration of Magaly Solier as Fausta.
Continue reading at:
gogeometry.com/wonder_world/berlin_festival_teta_asustada_milk_sorrow_golden_rectangle.html
Problem 250. Quadrilateral, sides, diagonals, midpoints, squares
Proposed Problem
See complete Problem 250 at:
gogeometry.com/problem/p250_quadrilateral_diagonals_midpoints_squares.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Problem 249. Triangle sides, medians, squares
Proposed Problem
See complete Problem 249 at:
gogeometry.com/problem/p249_triangle_sides_medians_squares.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Saturday, February 14, 2009
Ilya Bolotowsky, Black Diamond, Screenprint, 1978
Golden Rectangle
Ilya Bolotowsky (Russian/American, 1907-1981) became a leading early 20th-century painter in abstract styles in New York City. His work, a search for philosophical order through visual expression, embraced Cubism and Geometric abstraction and was much influenced by Dutch painter Piet Mondrian.
Black Diamond, Screenprint, 1978. By 1950 Bolotowsky introduced circular and diamond-shaped canvases followed by ovals and other unusual rectangles.
Click the figure below to see the interactive illustration of Black Diamond, Screenprint, 1978.
Continue reading at:
gogeometry.com/wonder_world/ilya_bolotowsky_black_diamond_golden_rectangle.html
Homage to the Square, 1965 by Josef Albers
Golden Rectangle
Josef Albers (1888 - 1976) was a German-born American artist (geometric abstraction) and educator whose work, both in Europe and in the United States, formed the basis of some of the most influential and far-reaching art education programs of the 20th century.
Homage to the Square. These paintings investigated the retinal effects of color. He published the fruits of this systematic research in a volume called, the Interaction of Color in 1963. Albers used nested squares to investigate color interaction.
Click the figure below to see the interactive illustration of Homage to the Square, 1965.
Continue reading at:
gogeometry.com/wonder_world/josef_albers_homage_square_golden_rectangle.html
Piet Mondrian, Composition II in Red, Blue, and Yellow, 1930
Golden Rectangle
Piet Mondrian was a Dutch painter, a pioneer of Geometric abstraction.
In the further attempt to simplify and perfect his images, he did not use any curved lines or organic shapes, he used only straight lines and geometric shapes. He also only used black, white, gray, and the three primary colors – bright red, blue, and yellow. The use of his simple geometric shapes and basic colors formed a new style or art movement called De Stijl.
Click the figure below to see the interactive illustration of Composition II in Red, Blue, and Yellow.
Continue reading at:
gogeometry.com/wonder_world/piet_mondrian_composition_ii_golden_rectangle.html
Thursday, February 12, 2009
Median length, Apollonius' Theorem
The following theorem has been attributed to Apollonius: In any triangle, the sum of the squares on any two sides is equal to twice the square on half the third side together with twice the square on the median which bisects the third side.
See complete illustration at:
gogeometry.com/geometry/median_length_apollonius_theorem.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Euclid's Elements Book II, Proposition 13: Law of Cosines
Acute Triangle
See complete illustration at:
gogeometry.com/geometry/euclid_elements_book_ii_proposition_13_cosines_law.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Euclid's Elements Book II, Proposition 12: Law of Cosines.
Obtuse Triangle
See complete illustration at:
gogeometry.com/geometry/euclid_elements_book_ii_proposition_12_cosines_law.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Wednesday, February 11, 2009
Composition VII by Wassily Kandinsky
Kaleidoscope
One of the most famous 20th-century artists, he is credited with painting the first modern abstract works. Kandinsky analyses in his writings the geometrical elements which compose every painting, namely the point and the line, as well as the physical support and the material surface on which the artist draws or paints and which he calls the basic plan.
Click the figure below to see the interactive illustration.
Continue reading at:
gogeometry.com/wonder_world/wassily_kandinsky_composition_vii_1.html
"On White II" by Wassily Kandinsky
Kaleidoscope
One of the most famous 20th-century artists, he is credited with painting the first modern abstract works. Kandinsky analyses in his writings the geometrical elements which compose every painting, namely the point and the line, as well as the physical support and the material surface on which the artist draws or paints and which he calls the basic plan.
Click the figure below to see the interactive illustration.
Continue reading at:
http://gogeometry.com/wonder_world/wassily_kandinsky_on_white_ii_1.html
Composition X by Wassily Kandinsky
Kaleidoscope
One of the most famous 20th-century artists, he is credited with painting the first modern abstract works. Kandinsky analyses in his writings the geometrical elements which compose every painting, namely the point and the line, as well as the physical support and the material surface on which the artist draws or paints and which he calls the basic plan.
Click the figure below to see the interactive illustration.
Continue reading at:
gogeometry.com/wonder_world/wassily_kandinsky_composition_x_1.html
Monday, February 9, 2009
Problem 248. Napoleon's Theorem III. Area Inner and outer Napoleon triangles
Inner Napoleon Triangle
See complete Problem 248 at:
gogeometry.com/problem/p248_napoleon_theorem_iii_area_inner_outer.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Sunday, February 8, 2009
Problem 247. Napoleon's Theorem II. Internal Equilateral triangles
Inner Napoleon Triangle
See complete Problem 247 at:
gogeometry.com/problem/p247_napoleon_theorem_inner_equilateral_triangle.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Saturday, February 7, 2009
Ekaterina Gordeeva and the Golden Rectangle
Golden Rectangle
Ekaterina Gordeeva (born May 28, 1971) often called Katia, Gordeeva is a Russian (former Soviet) pair skater. Together with her late partner and husband Sergei Grinkov, she was the 1988 and 1994 Olympic Champion.
Click the figure below to see the interactive illustration.
Continue reading at:
gogeometry.com/wonder_world/ekaterina_gordeeva_golden_rectangle.html
Lake Erie and the Golden Rectangle
Lake Erie is the fourth largest lake (by surface area) of the five Great Lakes, and the tenth largest globally.
On February 7, 2009, New York Times reported that one man died after more than 100 ice fisherman who ventured a mile onto the western Ohio shores of Lake Erie Saturday had to be rescued after an eight-mile long portion of ice they were on broke away amid warming conditions and starting drifting north.
An ice floe is a floating chunk of ice that is less than 10 kilometers (six miles) in its greatest dimension. Wider chunks of ice are called ice fields.
Click the figure below to see the interactive illustration of Lake Erie and the Golden Rectangle.
Continue reading at:
gogeometry.com/wonder_world/lake_erie_golden_rectangle.html
Alex Rodriguez and the Golden Rectangle
Golden Rectangle
Alex Rodriguez is a Dominican American Major League Baseball player. He currently plays third baseman for the New York Yankees. Rodriguez has been cited as among the best all–around players currently in Major League Baseball. He has also been compared with many all-time great players.
In February 2009, Sports Illustrated reported that Alex Rodriguez tested positive for anabolic steroids in 2003, the year in which baseball players were tested anonymously and without penalty to assess the level of steroid use in the game.
Click the figure below to see the interactive illustration.
Continue reading at:
gogeometry.com/wonder_world/alex_rodriguez_baseball_golden_rectangle.html
Versatile actor James Whitmore died of lung cancer
Golden Rectangle
James Whitmore (October 1, 1921 – February 6, 2009) was an American two-time Oscar Academy Award-nominated, Emmy- and Golden Globe-winning film actor. Whitmore died of lung cancer, Friday, Feb. 6, 2009, in his Malibu home, according to his son Steve Whitmore.
Click the figure below to see the interactive illustration.
Continue reading at:
gogeometry.com/wonder_world/whitmore_james_dead_golden_rectangle.html
Friday, February 6, 2009
Problem 246. Napoleon's Theorem I. External Equilateral triangles
Outer Napoleon Triangle
See complete Problem 246 at:
gogeometry.com/problem/p246_napoleon_theorem_external_equilateral_triangle.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Thursday, February 5, 2009
Elearn Geometry Problem 245: Parallelogram with Equilateral triangles. Congruence

See complete Problem 245 at:
gogeometry.com/problem/p245_parallelogram_equilateral_triangle_congruence.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Wednesday, February 4, 2009
Elearn Geometry Problem 244: Squares, Diagonals, Centers, Distance

See complete Problem 244 at:
gogeometry.com/problem/p244_square_centers_diagonal_vertex.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Triangle with Equilateral triangles, Rhombuses, Parallelograms

See complete Problem 243 at:
gogeometry.com/problem/p243_triangle_equilateral_parallelograms.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.
Tuesday, February 3, 2009
Elearn Geometry Problem 242: Triangle with Equilateral triangles, Parallelogram

See complete Problem 242 at:
gogeometry.com/problem/p242_triangle_equilateral_parallelogram.htm
Level: High School, SAT Prep, College geometry
Post your solutions or ideas in the comments.