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Recent Additions (Page 53 of 80)




Proposed Problem 148.
Quadrilateral, Area, Midpoints.


Proposed Problem 147.
Quadrilateral, Area, Midpoints, Triangle.


Proposed Problem 146. Varignon's
Theorem: Quadrilateral, Midpoints, Parallelogram, Area, Perimeter.


Proposed Problem 145. Four
Triangles, Incircle, Tangent and Parallel to Side, Incenters,
Circumcenters.


Pappus Theorem. Dynamic Geometry.
StepbyStep construction, Manipulation, and animation.


Proposed Problem 144. Four
Triangles, Incircle, Tangent and Parallel to Side, Inradii.


Proposed Problem 143. Four
Triangles, Incircle, Tangent and Parallel to Side, Circumradii.


Proposed Problem 142. Four
Triangles, Incircle, Tangent and Parallel to Side, Areas.


Proposed Problem 141. Triangle,
Incircle, Tangent , Parallel, Perimeters.


Proposed Problem 140. Triangle,
Excircle, Tangent, Semiperimeter.


El Condor Pasa, Mind map.


Proposed Problem 139. Triangle
Area, Orthic Triangle, Semiperimeter, Circumradius.


Proposed Problem 138. Nagel's
Theorem, Orthic Triangle, Altitudes, Circumradius, Perpendicular.


Go Geometry Puzzles Mind Map.


Proposed Problem 137.
Orthic Triangle, Altitudes, Perpendicular, Incircle, Collinear Points,
Parallelogram.


Proposed Problem 136. Orthic
Triangle, Altitudes, Perpendicular, Concyclic Points.


Proposed Problem 135. Orthic
Triangle, Altitudes, Perpendicular, Parallel.


Proposed Problem 134. Orthic
Triangle, Altitudes, Angle Bisectors, Orthocenter, Incenter.


Interactive Gergonne Line and Nobbs Points.
Dynamic Geometry.
StepbyStep construction, Manipulation, and animation.


Interactive Simson Line. Dynamic
Geometry.
StepbyStep construction, Manipulation, and animation.


Triangle, Medians, Six Circumcenters Concyclic.
Dynamic Geometry.
StepbyStep construction, Manipulation, and animation.
Prove proposition.


Trapezoid, Triangle, Diagonals, Midpoints.
Dynamic Geometry.
StepbyStep construction, Manipulation, and animation.
Prove proposition.


Congruence. Index..


Similarity, Ratios, Proportions.
Index.


Areas Index.


The Metamorphosis of the Cube Foldings and Unfolding between
Polygons and Polytopes.


Dynamic Geometry.
Triangle: Incircle, Perpendicular, Angle Bisector. Prove proposition


Proposed Problem 133.
Triangle, Angle Bisectors, Collinear Points.


Proposed Problem 132.
Triangle, 60 degree, Orthocenter, Congruence, Midpoint.


Survivor: the Inca Trail to Machu Picchu by Doug Johnson
A slideshow based on the author's hike of the Inca Trail.
Machu Picchu Slideshow.


Proposed Problem 131. Van Aubel
Theorem, Concurrent Cevians, Sum of Ratios.


Proposed Problem 130. Triangle,
Concurrent Cevians, Sum of Ratios.


Proposed Problem 129. Triangle,
Concurrent Cevians, Sum of Ratios.


Proposed Problem 128. Incenter of
a Triangle, Angle Bisectors, Sum of Ratios.

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