Triangles: Theorems and Problems 8

Geometry Problem 946.
Triangle, Quadrilateral, Area, Diagonal, Midpoint, Parallel.

Geometry Problem 945.
Triangle, Concurrent Lines, Cevians, Perpendicular, Angle Bisector.

Geometry Problem 944.
Triangle, Orthocenter, Altitude, Perpendicular, 90 Degrees, Parallel Lines.

Geometry Problem 943.
Triangle, Incircle, Inscribed Circle, Tangency Points, Parallel, Metric Relations.

Geometry Problem 942.
Triangle, Circles, Circumcircle, Sagitta, Incircle, Excircle, Inradius, Exradius, Metric Relations.

Geometry Problem 939.
Circle, Tangent, Secant, Chord, Parallel, Midpoint.

Geometry Problem 938.
Cyclic Quadrilateral, Triangle, Circumcircle, Circles, Circumcenter, Circumradius, Distance, Metric Relations.

Geometry Problem 937.
Triangle, Circumcircle, Circles, Tangent, Sides, Midpoint.

Geometry Problem 936.
Circle, Semicircle, Diameter, Tangent, Radius, Chord, Metric Relations.

Geometry Problem 935.
Square, Circle, Center, Perpendicular, Metric Relations.

Geometry Problem 933.
Square, Center, Transversal, Perpendicular, Metric Relations, Congruence.

Geometry Problem 932.
Square, Midpoint, Diagonal, Ratio 3:1, Angle Measure, Congruence.

Geometry Problem 931.
Square, Circle, Semicircle, Diameter, Triangle, Angle, Metric Relations.

Geometry Problem 930.
Acute Triangle, Altitudes, Circles, Diameter, Angle, Measure.

Geometry Problem 929.
Triangle, Orthocenter, Circumcircle, Reflection, Concurrency.

Geometry Problem 928.
Triangle, Midpoint, Median, Cevian, Concurrency, Area.

Geometry Problem 927.
Semicircle, Diameter, Radius, Equal Arcs, Chord, Triangle, Congruence.

Geometry Problem 926.
Two Equilateral Triangles, Midpoint, Perpendicular, Metric Relations.

Geometry Problem 924.
Quadrilateral, Diagonal, Perpendicular, Circle, Tangent, Midpoint, Metric Relations.

Geometry Problem 923.
Quadrilateral, Quadrangle, Obtuse Angle, Triangle, Diagonal, Inequality, Length.

Geometry Problem 922.
Circle, Tangent Lines, Tangency Points, Chord, Secant, Harmonic Mean.

Geometry Problem 921.
Right Triangle, Circumcircle, Arc, Midpoint, Tangency Point, Incircle.

Geometry Problem 920.
Triangle, Angles, 10, 20 Degrees, Congruence.

Geometry Problem 919.
Rhombus, Triangle, Perpendicular, 90 Degrees, Congruence.

Geometry Problem 918.
Triangle, Incenter, Incircle, Angle Bisector, Perpendicular, Metric Relations.

Geometry Problem 917.
Triangle, Congruence, Midpoints, Angle Bisector, Perpendicular.

Geometry Problem 916.
Cyclic Quadrilateral, Three Circles, Diameter, Congruence.

Geometry Problem 915.
Triangle, Intersecting Circles, Concyclic Points, Cyclic Quadrilateral.

Geometry Problem 914.
Triangle, Orthocenter, Angle Bisector, Parallel Lines, Midpoint.

Geometry Problem 913.
Right Triangle, Double Angle, Triple Angle, Metric Relations.

Geometry Problem 912.
Right Triangle, Double Angle, Triple Angle, Perpendicular Lines.

Geometry Problem 911.
Right Triangle, Double Angle, Triple Angle, Concyclic Points, Cyclic Quadrilateral.

Static Diagram of problem 902
Dynamic Geometry Problem 902
Triangle, Four Squares, Center, Concurrent Lines. GeoGebra, HTML5 Animation for Tablets

Geometry Problem 896
Triangle, Orthocenter, Midpoint, Median, Intersecting Circles, Diameter, Collinear Points.
GeoGebra, HTML5 Animation for Tablets

Geometry Problem 895
Triangle, Incircle, Tangency Points, Parallel line, Collinear Points.
GeoGebra, HTML5 Animation for Tablets

Geometry Problem 894
Triangle, Angle, 60 degrees, Incenter, Midpoint, Parallel Lines.
GeoGebra, HTML5 Animation for Tablets

Geometry Problem 893
Triangle, Circumcircle, Incenter, Circle, Tangent, Collinear Points.
GeoGebra, HTML5 Animation for Tablets

Geometry Problem 892
Triangle, 60 degrees, Orthocenter, Circumcenter.

Geometry Problem 889
Carnot's Theorem in an acute triangle, Circumcenter, Circumradius, Inradius. GeoGebra, HTML5 Animation for Tablets.

Geometry Problem 887
Triangle, Altitude, Angle Bisector, Perpendicular, Midpoint, Concyclic Points. GeoGebra, HTML5 Animation for Tablets.

Geometry Problem 882
Triangle, Angle x, 2x, 7x, Cevian, Congruence, Auxiliary Lines.

Geometry Problem 881
Triangle, three Squares, Centers, Areas.

Geometry Problem 880
Triangle, Midpoints, Sides, Perpendiculars, Hexagon, Area.

Geometry Problem 879
Square, Midpoint, Diagonal, Ratio 3:1, Angle Measure.

Geometry Problem 878
Square, Inscribed Circle, Quadrant, Center, Perpendicular, Metric Relations.

Geometry Problem 877
Square, Right Triangle, Similarity, Metric Relations, Transversal.

Geometry Problem 876
Equilateral Triangle, any Point, Perpendicular, Right Triangle Area, Sum of Areas.

Geometry Problem 875
Congruent Circles, Intersecting Circles, Secant, Center, Angle Trisection, Triple Angle.

Geometry Problem 874
Isosceles Triangle, Circumcircle, Circumcenter, Congruence.

Geometry Problem 873
Quadrilateral, Diagonal, Triangle, Angle Bisector, Congruence.

Geometry Problem 872
Quadrilateral, Triangle, Angle, 30, 90 degrees.

Geometry Problem 870
Triangle, Median, Three Squares, Centers, Vertices, Collinear Points, Midpoint.

Geometry Problem 869
Triangle, Median, Three Equilateral Triangles, Collinear Points, Midpoint.

Geometry Problem 867
Isosceles Triangle, Median, Perpendicular, Angle, Congruence.

Geometry Problem 865
Parallelogram, Diagonal, Midpoint, Side, Triangle, Parallel, Similarity.

Geometry Problem 864
Parallelogram, Diagonal, Congruence, Similarity, Metric Relations.

Geometry Problem 863
Circumscribed trapezoid, Inscribed Circle, Tangent, Metric Relations.

Geometry Problem 862:
Trapezoid, Parallel, Equal Areas, RMS, Root Mean Square
.

Geometry Problem 861
Triangle, Incircle, Parallel, Tangent, Metric Relations.

Geometry Problem 860
Triangle, Three Medians, Parallel, Parallelogram, Area, Congruence.

Geometry Problem 859
Isosceles Right Triangle, Angles,18, 45 Degrees, Congruence, Perpendicular bisector.

Geometry Problem 858
Isosceles Right Triangle, Cevian, Ratio 2:1, 45 Degrees, Congruence, Angles, Auxiliary Lines.

Geometry Problem 857
Triangle, Median, Midpoint, Angles, 30, 45 Degrees, Congruence, Auxiliary Lines.

Geometry Problem 856
Quadrilateral, Diagonals, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines.

Geometry Problem 855
Quadrilateral, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines.

Geometry Problem 854
Triangle, Parallel lines, Parallelogram, Areas, Similarity, Concurrent lines.

Geometry Problem 853
Online Geometry Problem 853: Square, Arc, Quadrant, Triangle, Perpendicular, Metric Relations.

Geometry Problem 852
Online Geometry Problem 852: Triangle, Incircle, Inradius, Tangent, Metric Relations.

Geometry Problem 851
Triangle, Triple side, Angles, 90 Degrees, Special Right triangle, Sides ratio 1:3.

Geometry Problem 850
Triangle, Double side, Angles, 90 Degrees. Special Right triangle.

Geometry Problem 849
Special Right triangle, Catheti or legs ratio 1:3, 18.5 Degrees. Double angle.

Geometry Problem 848
Special Right triangle, Catheti or legs ratio 1:2, 26.5 Degrees. Double angle.

Geometry Problem 847
van Lamoen Circle, Triangle, Medians, Centroid, Six Circumcenters, Concyclic Points.

Geometry Problem 846
Triangle, Medians, Centroid, Four Circumcenters, Concyclic Points, Cyclic Quadrilateral, Similarity.

Geometry Problem 845
Triangle, Medians, Centroid, Four Circumcenters, Perpendicular, Congruence, Similarity.

Geometry Problem 844
Triangle, Medians, Centroid, Four Circumcenters, Perpendicular, Congruence, Similarity.