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GoGeometry: Open Problems
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Open Geometry Problems - Index
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Geometry Problem
730.
Post
a solution
Triangle, Altitude, Orthocenter, Perpendicular, Concurrent Lines. |
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Geometry Problem
729.
Post
a solution
Triangle, Altitude, Orthocenter, Circumcircle, Perpendicular, Midpoint. |
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Geometry Problem
728.
Post
a solution
Triangle, Altitude, Perpendicular, Circumcircle, Midpoint, Intersecting Circles, Concurrency. |
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Geometry Problem
727.
Post
a solution
Triangle, Isosceles, Congruence, Angles, Measurement. |
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Geometry Problem
726.
Post
a solution
Isosceles Triangle, Perpendicular, Midpoint, 90 Degrees. |
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Geometry Problem
725.
Post
a solution
Kurschak's Dodecagon, Square, Equilateral Triangle, Midpoints, 30, 60 Degrees. |
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Geometry Problem
724.
Post
a solution
Circumscribed Quadrilateral, Circle, Angle, Incenter, Half
the Measure. |
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Geometry Problem
721.
Post
a solution
Triangle, Orthocenter, Circumcircle, Altitude, Collinear points. |
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Geometry Problem
715.
Post
a solution
Triangle, Altitudes, Parallel, Circumcircle, Angle, Measurement. |
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Geometry Problem
710.
Post
a solution
Parallelogram, Midpoint, Diagonal, Collinear Points, Metric Relations, Triangle, Similarity, Congruence. |
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Geometry Problem
705.
Post
a solution
Intersecting Circles, Diameter, Angles, Measurement. |
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Geometry Problem
701.
Post
a solution
Intersecting Circles, Diameter, Perpendicular, Angles, Congruence. |
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Geometry Problem 696.
Post
a solution
Triangle, Angles, Auxiliary Construction, Congruence, Mind Map, Polya. |
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Geometry Problem 693.
Post
a solution
Square, Inscribed and Circumscribed Circle, Areas, Mind Map, Polya. |
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Geometry Problem 691.
Post
a solution
Isosceles Triangle, 80-80-20 Degrees, Angles, Congruence, Mind Map, Polya. |
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Problem 690: Distance between the Incenter and the Centroid of a
Triangle.
Post
a solution
Formula in terms of the sides a,b,c. |
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Geometry Problem 689.
Post
a solution
Triangle, Three Excircles, Tangency points, Tangent lines, Concurrent Lines, Mind Map. |
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Geometry Problem 688.
Post
a solution
Triangle, Angles, 10, 20, 30, 40, 60 Degrees, Measure, Mind Map, Polya. |
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Geometry Problem 687.
Post
a solution
Triangle, Three Excircles, Tangency points, Concurrent Lines. |
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Geometry Problem 685
Post a solution
Isosceles Triangle, 100-40-40 Degrees, Angles, Congruence. |
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Geometry Problem 675.
Post
a solution
Intersecting Circles, Secant, 45 and 90 Degrees, Collinear Points. |
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Geometry Problem 674.
Post
a solution
Triangle, Altitude, Angles. |
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Geometry Problem 660.
Post
a solution
Triangle, Circle, Diameter, Perpendicular Lines. |
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Geometry Problem 659.
Post
a solution
Parallelogram, Parallel Lines, Collinear Points. |
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Geometry Problem 658.
Post
a solution
Triangle, Altitudes, Diameter, Circle, Angles. |
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Geometry Problem 656.
Post
a solution
Triangle, Cevian, Concurrent Lines. |
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Geometry Problem 638
Post a solution
Arbelos and Inscribed Circle: Concyclic Points. |
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Geometry Problem 633
Post a solution
Triangle, Parallel Lines, Intersecting Lines. |
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Geometry Problem 632.
Post a solution
Triangle, Interior and Exterior Angle Bisectors, Midpoints, Collinear Points. |
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Geometry Problem 630: Clawson Point.
Post a solution
Orthic and Extangents Triangles, Concurrent lines. |
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Geometry Problem 629
Post a solution
Triangle, Perpendicular to Sides, Intersecting Lines, Altitude. |
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Geometry Problem 621
Post a or solution
Three Rectangles, Diagonals, Centers, Angles. |
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Geometry Problem
620
Post a comment or solution
Three Rectangles, Diagonals, Centers, Angles. |
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Geometry Problem
616
Post a comment or solution
Parallelogram, Diagonals, Intersecting Lines, Parallel Lines. |
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Geometry Problem
613
Post a solution
Altitude of a Triangle, Perpendicular, Collinear Points. |
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Geometry Problem
612
Post a solution
Altitude of a Triangle, Perpendicular, Congruence. |
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Geometry Problem
611
Post a solution
Altitude of a Triangle, Perpendicular, Collinear Points, Parallel. |
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Geometry Problem
610
Post a solution
Intersecting Circles, Radius, Parallel, Common Tangent, Angle, 90 Degrees. |
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Geometry Problem
609
Post a solution
Triangle, Perpendiculars, 90 Degrees, Collinearity. |
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Geometry Problem
608
Post a solution
Square with Right Triangles, Metric Relations, Congruence, Measurement. |
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Geometry Problem
607
Post a solution
Intersecting Circles, Triangles, Metric Relations, Measurement. |
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Geometry Problem
601
Post a solution
Cyclic Quadrilateral, Incenter, Excenter, Rectangle. |
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Geometry Problem
600
Post a solution.
Circle, Area, Tangent, Semicircle, Tangency Point. |
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Geometry Problem
593
Post a solution.
Triangle, Circumcircle, Collinear Points. |
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Geometry Problem
590
Post a solution.
Triangle, Incenter, Incircle, Tangency Point, Midpoint, Areas. |
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Geometry Problem
586
Post a solution.
Cyclic Quadrilateral, Diagonals, Any Point, Circumcenters, Circumcircles, Concurrency. |
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Problem 535.
Post a solution.
Sawayama - Thebault's theorem: Triangle, Incircle, Circle, Center, Tangent,
Collinear. |
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Problem
534.
Post a solution.
Right Triangle, Squares, Perpendicular, Dissection, Areas. |
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Problem 454.
Post a solution.
Triangle, Incircle, Inradius, Tangent, Circle, Radius. |
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Problem 350.
Post
a solution.
Triangle, Cevian, Incircles, Tangents, Tangency Point, Angles. |
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Problem 345.
Post
a solution.
Equal circles, Tangents, Concurrent lines, Hexagon, Semiperimeter. |
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Brianchon's Theorem in a Circumscribed Hexagon.
Post
a solution. |
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Brianchon Corollary, Circumscribed Hexagon, Concurrency lines.
Post
a solution. |
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Carnot's
Theorem in an Acute Triangle.
Post
a solution. |
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Carnot's
Theorem in an Obtuse Triangle.
Post
a solution. |
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