Geometry Theorems and Problems - Recent Additions (Page 4 of 15)

Geometry Problem 704.
Triangle, Orthocenter, Altitude, Midpoint, Perpendicular.

Geometry Problem 703.
Triangle, Incircle, Tangency point, Diameter, Congruence.

Geometry Problem 702.
Triangle, Circumcircle, Parallel, Concyclic Points.

Geometry Problem 701.
Intersecting Circles, Diameter, Perpendicular, Angles, Congruence.

Concyclic Points.
 

Geometry Problem 700.
Equilateral Triangle, Circle, Circular Segment, Midpoint of a side, Metric Relations.

Geometry Problem 699.
Equilateral Triangle, Circle, Circular Segment, Midpoint, Metric Relations.

Circular Segment. Index.
Theorems and Problems. 

Geometry Problem 698.
Quadrilateral, Diagonal, Angle Bisector, Triangle, 120 Degrees.

Geometry Problems 691 - 700.
Triangle, Quadrilateral, Circle, Metric Relations, Square, 30-60-120 Degrees, Area, Congruence.

Geometry Problem 697.
Square, Circle, Sector, Segment, Tangent, Inscribed, Congruence, Mind Map, Polya.

Geometry Problem 696.
Triangle, Angles, Auxiliary Construction, Congruence, Mind Map, Polya.

Geometry Problem 695.
Triangle, Angles, Auxiliary Construction, Congruence, Mind Map, Polya.

Geometry Problem 694.
Triangle, Angles, 30 Degrees, Auxiliary Construction, Mind Map, Polya.

Geometry Problem 693.
Square, Inscribed and Circumscribed Circle, Areas, Mind Map, Polya.

Geometry Problem 692.
Quatrefoil, Four Equal Circles and a Circle Inscribed in a Square, Areas, Mind Map, Polya.

Geometry Problem 691.
Isosceles Triangle, 80-80-20 Degrees, Angles, Congruence, Mind Map, Polya.

Problem 690: Distance between the Incenter and the Centroid of a Triangle.
Formula in terms of the sides a,b,c.

Geometry Problems 681 - 690.
Triangle, Circle, 60 Degrees, Incenter, Circumcenter, Orthocenter, Parallelogram, Metric Relations, Congruence, Similarity.

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

Geometry Problem 688.
Triangle, Angles, 10, 20, 30, 40, 60 Degrees, Measure, Mind Map, Polya.

Geometry Problem 687.
Triangle, Three Excircles, Tangency points, Concurrent Lines.

Geometry Problem 686.
Triangle, Three Excircles, Tangency points, Tangent lines, Semi-perimeter, Congruence.

Geometry Problem 685
Isosceles Triangle, 100-40-40 Degrees, Angles, Congruence.

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

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

Geometry Problem 682: Gergonne External Point.
Triangle, Excircle, Tangency points, Concurrent lines, Semiperimeter, Ceva theorem.

Geometry Problem 681: Gergonne Point.
Triangle, Incircle, Tangency points, Concurrent lines, Semiperimeter, Ceva theorem.

Geometry Problem 680.
Concentric Circles, Radii, Chords, Perpendicular, Metric Relations.

100 Geometry Problems Collection

Geometry Problem 679.
Triangle, Circle, Median, Proportion.

Geometry Problem 678.
Triangle, Simson Line, Circumcircle, Tangent, Parallel, Perpendicular, Collinear Points.

Geometry Problem 677.
Parallelogram, Midpoint, Diagonal, Metric Relations.

Geometry Problem 676.
Circles, Diameter, Tangent, Chord, Metric Relations.

Geometry Problem 675.
Intersecting Circles, Secant, 45 and 90 Degrees, Collinear Points.

Geometry Problem 674.
Triangle, Altitude, Angles.

Geometry Problem 673.
Internally tangent circles, Chord, Tangent, Metric Relations.

Geometry Problem 672.
Internally tangent circles, Chord, Tangent, Geometric Mean.

Geometry Problem 671.
Triangle, Cevian, Angles, Congruence.

Geometry Problem 670.
Triangle, 60 Degrees, Orthocenter, Incenter, Circumcenter, Congruence.

Geometry Problem 669.
Triangle, Circumcircle, Incenter, Midpoint, Collinear points, Mind Map.

Geometry Problem 668.
Right triangle, Incircles, Parallel, Common Tangent, Mind Map.

Geometry Problem 667.
Intersecting Circles, Secant, Tangent, Metric Relations, Mind Map.

Geometry Problem 666.
Intersecting Circles, Secant, Tangent, Concyclic points, Mind Map.

Geometry Problem 665.
Intersecting Circles, Secant, Tangent, Angles, Mind Map.

Geometry Problem 664.
Triangle, 60 Degrees, Orthocenter, Incenter, Circumcenter, Angles, Triangle centers.

Geometry Problem 663.
Scalene Triangle, 60 Degrees, Altitude, Angle Bisector, Perpendicular Bisector, Concurrent lines.

Video solution: Problems 1-6 (Spanish version)
By Eder Contreras and Cristian Baeza, Chile.

Geometry Problem 662.
Triangle, Incenter, Circumcenter, Orthocenter, Circle, Angle, Measurement.

Geometry Problem 661.
Intersecting Circles, Centers, Secant, Parallelogram.

Geometry Problem 660.
Triangle, Circle, Diameter, Perpendicular Lines.

Geometry Problem 659.
Parallelogram, Parallel Lines, Collinear Points.

Geometry Videos Index

Geometry Problem 658.
Triangle, Altitudes, Diameter, Circle, Angles.

Geometry Definitions.

Geometry Problem 657.
Triangle, Incircle, Tangency Points, Parallel Lines, Congruence.

Geometry Definitions.

Geometry Problem 656.
Triangle, Cevian, Concurrent Lines.

Dynamic Geometry Software: GeoGebra 3.2 Help Document
GeoGebra is a dynamic geometry software. Constructions can be made with points, vectors, segments, lines, polygons, conic sections, and functions.
Interactive Mind Map

Geometry Problem 655.
Archimedes Book of Lemmas: Proposition 15
Circle, Inscribed Regular Pentagon, Radius.

Semicircle. Index.
Theorems and Problems.

Geometry Problem 654.
Archimedes Book of Lemmas: Proposition 14
Salinon, Semicircles, Diameter, Circle, Area.

Geometry Problem 653.
Archimedes Book of Lemmas: Proposition 13
Circle, Chord, Perpendicular, Congruence.

Geometry Problem 652.
Archimedes Book of Lemmas: Proposition 12
Perpendicular chords, Arcs, Radius.

Geometry Problem 651.
Archimedes Book of Lemmas: Proposition 11
Perpendicular chords, Arcs, Radius.

Geometry Problem 650.
Tangent Circles, Diameter, Radius, Chord, Perpendicular.

Geometry Problem 649.
Archimedes Book of Lemmas: Proposition 10
Tangent, Chord, Parallel, Midpoint.

Geometry Problem 648.
Archimedes Book of Lemmas: Proposition 9
Perpendicular chords, Arcs.

Geometry Problem 647.
Archimedes Book of Lemmas: Proposition 8
Angle trisection. Neusis construction.

Geometry Problem 646.
Archimedes Book of Lemmas: Proposition 7
Square,Inscribed and Circumscribed Circles, Area.