Angles 30, 60, 90, 120, Theorems and Problems - Table of Content 1

Geometry Problem 1580: 60-Degree Triangle Challenge: Uncover AD Using Excenter and Circumcircle Clues.

Geometry Problem 1566: Demonstrate AC Equals AE + CD in an Equilateral Triangle ABC Involving Cevians and 60 Degrees..

Geometry Problem 1496.
Triangle, Congruence, Isosceles, Double Angle, 30 Degrees.

Geometry Problem 1495.
Circle, Parallel Chords, 30 Degree Angle, Radius Squared.

Geometry Problem 1433.
Tangent Circles, Diameter, Perpendicular, Midpoint, Measurement, Poster Typography, iPad Apps.

Geometry Problem 1429.
Triangle, Median, 15-30 degree, Angle, Congruence.

Geometry Problem 1356.
Quadrilateral, Triangle, Angle, 30 Degrees, Congruence.

Geometry Problem 1353.
Tangent Circles, Perpendicular Diameters, Congruence, 30 Degrees.

Geometry Problem 1346.
Equilateral Triangle, Point on the Incircle, Altitude, Perpendicular, Sum of Squares, Distance.

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

Geometry Problem 1323.
Square, Angle Trisector, Diagonal, Regular Dodecagon, Area, 30-60 degrees.

Geometry Problem 1304.
Triangle, 120 Degrees, Angle Bisector, Measurement.

Geometry Problem 1303.
Triangle, 60 Degrees, Angle Bisector, Measurement.

Geometry Problem 1299.
Triangles, Interior Point, Angles, 30 degrees.

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

Geometry Problem 1286.
Triangle, Quadrilateral, 60, 135, 105 Degree Angles, Congruence, Measurement.

Geometry Problem 1285.
Triangle, Quadrilateral, 60, 150, 90 Degree Angles, Congruence, Measurement.

Geometry Problem 1238
Square, Equilateral Triangle, Metric Relations. Mobile Apps.

Geometry Problem 1234
Quadrilateral, 60 Degrees, Midpoint, Congruence, Cyclic Quadrilateral, Concyclic Points.

Geometry Problem 1230
Quadrilateral, 60 Degrees, Congruence, Metric Relations.

Geometry Problem 1225
Equilateral Triangle, Circumcircle, Angle Bisector, Congruence.

Geometry Problem 1222
Doubling the Cube, Triangle, 90, 120 degrees, Perpendicular, Congruence.

Geometry Problem 1220
Equilateral Triangles, Midpoints, 60 Degrees, Congruence.

Geometry Problem 1219
Equilateral Triangles, Midpoints, 60 Degrees, Congruence, Rhombus.

Geometry Problem 1218
Scalene Triangle, Equilateral Triangles, Midpoints, 60 Degrees, Congruence.

Geometry Problem 1180
Quadrilateral, 120 Degrees, Diagonals, Perpendicular.

Geometry Problem 1161.
Scalene Triangle, 60 Degrees, Angle, Orthocenter, Circumcenter, Equilateral Triangle, Congruence.

Geometry Problem 1120.
Isosceles Right Triangle, 120 Degree, Angle, Equilateral, Metric Relations.

Geometry Problem 1062.
Scalene Triangle with an angle of 60 degrees, Euler Line, Orthocenter, Circumcenter, Distance, Congruence, Transversal.

Geometry Problem 1000.
Scalene Triangle, Isosceles, Angle, 120 Degree, Midpoint, Distance, Equilateral, Congruence, Perpendicular, Metric Relations.

Geometry Problem 992.
Triangle, Interior Point, Angles, 20, 30 , 40, 50 Degree.

Geometry Problem 988.
Right Triangle, Cevians, Angles, 30 Degrees, Triple Angle.

Geometry Problem 964.
Right Triangle, Cevians, Angles, 10, 20, 30 Degrees.

Geometry Problem 956.
Two Equilateral Triangles, Center, Collinear Points, Midpoint, Right Triangle, 30, 60, 90 Degrees.

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

iPad Apps: Isometric.
Hexagons, Rhombus 60-120 degrees.

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

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

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 831
Quadrilateral, Diagonal, Midpoint, Opposite Angles, Congruence, Parallelogram.

Geometry Problem 830
Quadrilateral, Triangle, Angles, 30 degrees, Congruence.

Geometry Problem 820.
Triangle, Cevian, Angles, 30 Degrees.

Geometry Problem 819.
Quadrilateral, Triangle, Angles, 30 degrees.

Geometry Problem 814.
Two Equilateral Triangles with a common Vertex, Angle.

Geometry Problem 761
Scalene Triangle with an angle of 60 degrees, Euler Line, Equilateral Triangle.

Geometry Problem 754.
Equilateral Triangle, Center, Angle, 60 Degrees, Perimeter.

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

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

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