Geometry Problem 1455: Nagel Point, Excircles, Incircle, Congruent Segments

Interactive step-by-step animation using GeoGebra. Post your solution in the comment box below.
Level: Mathematics Education, High School, Honors Geometry, College.

Details: Click on the figure below.

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Geometry Problems 681-690: Triangle, Incircle, Excircle, Ceva, Semiperimeter, Concurrency, Gergonne, Nagel Point

Ten Geometry Problems
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Zoom Problems 681 - 690

Level: High School, College geometry

Problem 689: Triangle, Three Excircles, Tangency points, Tangent lines, Concurrent Lines, Mind Map

Geometry Problem
Level: Mathematics Education, High School, Honors Geometry, College.

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Problem 684: Outer Nagel Point, Triangle, Excircles, Tangency points, Concurrent lines, Semi-perimeter, Ceva theorem

Geometry Problem
Level: Mathematics Education, High School, Honors Geometry, College.

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Problem 683: Nagel Point, Triangle, Excircles, Tangency points, Concurrent lines, Semi-perimeter, Ceva theorem

Geometry Problem
Level: Mathematics Education, High School, Honors Geometry, College.

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Nagel Point Puzzle

22 pieces of polygons
The lines connecting each vertex of a triangle ABC with the point of tangency between the opposite side and the opposite excircle are concurrent at a point called the Nagel point.



Continue reading at:
gogeometry.com/puzzle/Puzzle_Nagel_point_center.htm

Triangle Centers: Nagel Point Proof

Visual illustration
The lines connecting each vertex of a triangle ABC with the point of tangency between the opposite side and the opposite excircle are concurrent at a point called the Nagel point.



See complete interactive proof with animation and key concepts at:
www.gogeometry.com/nagel_point1.htm

Level: High School, SAT Prep, College geometry

Elearn Geometry Problem 139

See complete Problem 139
Triangle Area, Orthic Triangle, Semiperimeter, Circumradius. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.

Elearn Geometry Problem 138 Nagel's Theorem

See complete Problem 138
Nagel's Theorem, Orthic Triangle, Altitudes, Circumradius, Perpendicular. Level: High School, SAT Prep, College geometry

Post your solutions or ideas in the comments.