College Geometry Online, eLearning

Online Geometry: Area of a triangle, Theorems and Problems - Table of Content

Area of a Triangle, Theorems and Problems


Heron's Formula.
Key facts and
a purely geometric step-by-step proof.

Area of a Right Triangle, Theorems and Problems

Area of a Right Triangle, Theorems and Problems.

Varignon and Wittenbauer parallelograms. Quadrilateral: midpoints and trisection points of the edges. Triangle areas.


Routh's theorem index

Routh's Theorem - Index
Triangle, Cevians, Area, Ratio.

Marion Walter's theorem and related topics

Marion Walter's Theorem and Related Topics: Index

Geometry Problem 1465

Geometry Problem 1465.
Tangential Quadrilateral, Incenter, Inscribed Circle, Equal Sum of Areas. Step-by-step Illustration using GeoGebra.

Geometry Problem 1464

Geometry Problem 1464.
Quadrilateral, Interior Point, Midpoint of Sides, Equal Sum of Areas. Step-by-step Illustration using GeoGebra.

Geometry Problem 1463

Geometry Problem 1463.
Parallelogram, Interior Point, Opposite Triangles with Equal Sum of Areas. Step-by-step Illustration using GeoGebra.

Geometry Problem 1458

Geometry Problem 1458.
Triangle, Incircles, Excircle, Area, Step-by-step Illustration using GeoGebra.

Geometry Problem 1456

Geometry Problem 1456.
Altitudes, Orthic Triangle, Circumcircle, Parallel lines, Similarity, Area, iPad. Step-by-step illustration using GeoGebra.

Problem 1430

Geometry Problem 1430.
Regular Octagon, Area, Equivalent Figures, Poster, Conformal Mapping.

Problem 1428

Geometry Problem 1428.
Intersecting Circles, Tangent Line, Triangle, Square, Area.

Problem 1426

Geometry Problem 1426.
Two Squares, Collinear Points, Triangle, Quadrilateral, Sum of the Areas.

Problem 1424

Geometry Problem 1424.
Triangle, Parallelogram, Trapezoid, Area, Diagonal, Measurement.

Problem 1423

Geometry Problem 1423.
Triangle, Area, Three Equal Angles, Circumradius, Measurement.

Problem 1422

Geometry Problem 1422.
Triangle, Transversal, Cevian, Area, Measurement.

Problem 1391

Geometry Problem 1391.
Two Triangles, Ratio of Areas, Circumcircle.

Problem 1381 Parallelogram, Triangle, Area

Geometry Problem 1381.
Parallelogram, Exterior Point, Triangle, Area.

Geometry problem 1345

Geometry Problem 1345.
Three Equilateral Triangles, Center, Area, Common Vertex.

Geometry problem 1310

Geometry Problem 1310.
Square, Center, Right Triangle, Area, Measurement.

Geometry problem 1305

Geometry Problem 1305.
Triangle, Circumcircle, Angle Bisector, Arc, Perpendicular, Area.

Heron Triangle Area Medians

Geometry Problem 1296.
Heron's Formula, Area of a triangle in terms of the three medians.

Geometry problem 1288

Geometry Problem 1288.
Triangle, 30-50-100 Degrees, Area, Inradius, Metric Relations, Measurement.

Geometry problem 1287

Geometry Problem 1287.
Triangle, 40-100-40 Degrees, Congruence, Area, Metric Relations, Measurement.

Geometry problem 1279

Geometry Problem 1279.
Parallelogram, Midpoint, Triangle, Area, 3/10.

Geometry problem 1274

Geometry Problem 1274.
Isosceles Triangle, 80-20-80 Degrees, Area, Inradius, Circumradius, Angle Bisector, Metric Relations, Measurement.

Geometry problem 1252

Geometry Problem 1252.
Triangle, Circle, Circumcircle, Altitude, Area, Hexagon, Perpendicular, 90 Degrees. Mind Map.

Geometry problem 1249

Geometry Problem 1249.
Cyclic Quadrilateral, Circle, Triangle, Circumcircle, Angle Bisector, Parallel Lines, Area.

Geometry problem 1211

Geometry Problem 1211
Right Triangle, Altitude, Angle Bisector, 45 Degrees, Metric Relations, Area.

Geometry problem 1208

Geometry Problem 1208
Triangle, Circle, Excircle, Excenter, Diameter, Perpendicular, 90 Degrees, Equal Areas.

Geometry problem 1201

Geometry Problem 1201
Triangle, Interior Perpendicular Bisector, Midpoint, Area.

Geometry problem 1200

Geometry Problem 1200
Square, Right Triangle, Perpendicular, 90 Degrees, Equal Areas.

Geometry problem 1198

Geometry Problem 1198
Right Triangle, Square, Rectangle, Quadrilateral, Altitude, Equal Areas.

Geometry problem 1197

Geometry Problem 1197
Four Squares, Four Triangles, Equal Areas.

Geometry problem 1192

Geometry Problem 1192
Trapezoid, Triangle, Diagonal, Midpoint, Area, Parallel.

Geometry problem 1188

Geometry Problem 1188
Triangle, Parallelogram, Parallel Lines, Trapezoid, Area.

Geometry problem 1187

Geometry Problem 1187
Triangle, Quadrilateral, Midpoints, Area.

Geometry problem 1186

Geometry Problem 1186
Right Triangle, Square, Inscribed Circle, Tangent, Quadrilateral, Area.

Geometry problem 1171

Geometry Problem 1171
Area of a Triangle in terms of the three altitude or heights ha, hb, hc.

Geometry problem 1170

Geometry Problem 1170
Area of a Triangle in terms of the three sides, a-b-c.

Geometry problem 1160

Geometry Problem 1160.
Triangle, Three Squares, Area, Equivalent Triangles.

Geometry problem 1155

Geometry Problem 1155.
Right Triangle, Altitude, Incenter, Incircle, Area.

Geometry problem 1131

Geometry Problem 1131.
Triangle Area, Two Cevians, Equal Product of Areas.

Geometry problem 1124

Geometry Problem 1124.
Triangle, Median, Two Squares, Area.

Geometry problem 1123

Geometry Problem 1123.
Hexagon, Triangle, 90 Degrees, Perpendicular Lines, Vertices, Area.

Geometry Problem 1112

Geometry Problem 1112.
Triangle, Excenters, Circumcircle, Circle, Hexagon, Area.

Geometry Problem 1111

Geometry Problem 1111.
Right Triangle, External Squares, Cathetus, Angle Bisector, Area, Geometric Mean.

Geometry Problem 1091

Geometry Problem 1091.
Square, Perpendicular, Distance, Area, Center.

Geometry Problem 1089

Geometry Problem 1089.
Square, Semicircle, Tangent, Triangle, Area.

Geometry Problem 1082

Geometry Problem 1082.
Square, Circle, Center, Radius, Side, Isosceles Triangle, 90 Degrees, Area.

Geometry Problem 1058

Geometry Problem 1058.
Triangle, Sum of the Areas, Altitude, Perpendicular, Circumcircle, Circle, Diameter.

Geometry Problem 1057

Geometry Problem 1057.
Triangle, Area, Circle with Perpendicular Diameters, Tangent, Secant.

Geometry Problem 1055

Geometry Problem 1055.
Triangle, Altitude, Perpendicular, Area, Circumradius, Circle.

Geometry Problem 1051

Geometry Problem 1051.
Triangle, Square, Semicircle, Arc, Area.

Geometry Problem 1037

Geometry Problem 1037.
Triangle, Three equal Incircles, Tangent lines, Inradius, Length.

Geometry Problem 1036

Geometry Problem 1036.
Triangle, Three equal Incircles, Tangent lines, Inradius, Equal Inradii.

Geometry Problem 1035

Geometry Problem 1035.
Triangle, Three equal Incircles, Tangent lines, Equivalent triangles, Equal area.

Geometry Problem 1033

Geometry Problem 1033.
Triangle, Angle Obtuse, Circumcircle, Diameter, Area.

Geometry Problem 983

Geometry Problem 983.
Regular Hexagon, A point and six triangles, Areas.

Geometry Problem 982

Geometry Problem 982.
Triangle, Excenters, Excentral Triangle, Circumcenter, Area, Hexagon.

Geometry Problem 981

Geometry Problem 981.
Triangle, Concurrent Cevians, Midpoints, Area, Hexagon.

Geometry Problem 969

Geometry Problem 969.
Equilateral Triangle, Rectangle, Common Vertex, Right Triangles Areas.

Geometry Problem 962

Geometry Problem 962.
Triangle, Two Cevians, Areas, Equal Products.

Problem 928

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

Geometry Problem 880

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

Geometry Problem 876

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

Triangle, Three Medians, Parallel, Parallelogram, Area, Congruence

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

Problem 854: Triangle, Parallel lines, Parallelogram, Areas, Similarity, Concurrent lines

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

Regular Hexagon, Midpoints, Equilateral Triangle

Geometry Problem 791
Regular Hexagon, Midpoints of Side and Diagonal, Equilateral Triangle, Area.

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HomeGeometry | Areas | Email | Post a comment | by Antonio Gutierrez
Last updated: Mar 9, 2022