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Angles 30, 60, 90, 120, Theorems and Problems - Table of Content 1
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![Geometry Problem 1566](../school-college/6/p1566-equilateral-triangle-cevian-60-degrees-mystery-sum-of-segments-tutoring-1.jpg) |
Geometry Problem 1566:
Demonstrate AC Equals AE + CD in an Equilateral Triangle ABC Involving Cevians and 60 Degrees.. |
![Geometry Problem 1496](../school-college/5/p1496-triangle-double-angle-isosceles-30-degree-congruence-1.jpg) |
Geometry
Problem 1496.
Triangle, Congruence, Isosceles, Double Angle, 30 Degrees. |
![Geometry Problem 1495](../school-college/5/p1495-circle-parallel-chords-30-degree-square-radius-1.jpg) |
Geometry
Problem 1495.
Circle, Parallel Chords, 30 Degree Angle, Radius Squared. |
![Problem 1433](../school-college/5/p1433-tangent-circles-line-midpoint-1.jpg) |
Geometry Problem 1433.
Tangent Circles, Diameter, Perpendicular, Midpoint, Measurement,
Poster Typography, iPad Apps. |
![Problem 1429](../school-college/5/p1429-triangle-median-angle-15-30-degree-1.jpg) |
Geometry Problem 1429. Triangle, Median, 15-30 degree, Angle, Congruence. |
![Geometry problem 1356](../school-college/4/p1356-triangle-30-degrees-angle-congruence-tutoring-1.jpg) |
Geometry Problem 1356.
Quadrilateral, Triangle, Angle, 30 Degrees, Congruence. |
![Geometry problem 1353](../school-college/4/p1353-tangent-circle-congruence-30-degrees-1.jpg) |
Geometry Problem 1353. Tangent Circles, Perpendicular Diameters, Congruence, 30 Degrees. |
![Geometry problem 1346](../school-college/4/p1346-equilateral-triangle-incircle-altitude-tutoring-1.jpg) |
Geometry Problem 1346. Equilateral Triangle, Point on the Incircle, Altitude, Perpendicular, Sum of Squares, Distance. |
![Geometry problem 1345](../school-college/4/p1345-equilateral-triangle-common-vertex-center-area-1.jpg) |
Geometry Problem 1345. Three Equilateral Triangles, Center, Area, Common Vertex. |
![Geometry problem 1323](../school-college/4/p1323-square-equilateral-triangle-dodecagon-1.jpg) |
Geometry Problem 1323.
Square, Angle Trisector, Diagonal, Regular Dodecagon, Area, 30-60 degrees. |
![Geometry problem 1304](../school-college/4/p1304-triangle-120-degrees-angle-bisector-1.jpg) |
Geometry Problem 1304.
Triangle, 120 Degrees, Angle Bisector, Measurement. |
![Geometry problem 1303](../school-college/4/p1303-triangle-60-degrees-angle-bisector-1.jpg) |
Geometry Problem 1303.
Triangle, 60 Degrees, Angle Bisector, Measurement. |
![Geometry problem 1299](../school-college/3/p1299-triangle-angle-30-degree-1.jpg) |
Geometry Problem 1299.
Triangles, Interior Point, Angles, 30 degrees. |
![Geometry problem 1288](../school-college/3/p1288-triangle-50-100-degrees-measurement-1.jpg) |
Geometry Problem 1288.
Triangle, 30-50-100 Degrees, Area, Inradius, Metric Relations, Measurement. |
![Geometry problem 1286](../school-college/3/p1286-quadrilateral-60-135-105-degrees-measurement-1.jpg) |
Geometry Problem 1286.
Triangle, Quadrilateral, 60, 135, 105 Degree Angles, Congruence, Measurement. |
![Geometry problem 1285](../school-college/3/p1285-quadrilateral-60-150-90-degrees-measurement-1.jpg) |
Geometry Problem 1285.
Triangle, Quadrilateral, 60, 150, 90 Degree Angles, Congruence, Measurement. |
![Geometry problem 1238](../school-college/3/p1238-square-equilateral-triangle-metric-relation-mobile-apps-1.jpg) |
Geometry Problem 1238
Square, Equilateral Triangle, Metric Relations. Mobile Apps. |
![Geometry problem 1234](../school-college/3/p1234-quadrilateral-60-degrees-cyclic-concyclic-midpoint-1.jpg) |
Geometry Problem 1234
Quadrilateral, 60 Degrees, Midpoint, Congruence, Cyclic Quadrilateral, Concyclic Points. |
![Geometry problem 1230](../school-college/3/p1230-quadrilateral-equilateral-triangle-metric-relations-1.jpg) |
Geometry Problem 1230
Quadrilateral, 60 Degrees, Congruence, Metric Relations. |
![Geometry problem 1225](../school-college/3/p1225-equilateral-triangle-bisector-circle-congruence-1.jpg) |
Geometry Problem 1225
Equilateral Triangle, Circumcircle, Angle Bisector, Congruence. |
![Geometry problem 1222](../school-college/3/p1222-doubling-the-cube-triangle-90-120-degrees-class-1.jpg) |
Geometry Problem 1222
Doubling the Cube, Triangle, 90, 120 degrees, Perpendicular, Congruence. |
![Geometry problem 1220](../school-college/3/p1220-scalene-equilateral-triangles-midpoint-class-1.jpg) |
Geometry Problem 1220
Equilateral Triangles, Midpoints, 60 Degrees, Congruence. |
![Geometry problem 1219](../school-college/3/p1219-equilateral-triangles-midpoint-rhombus-tutor-1.jpg) |
Geometry Problem 1219
Equilateral Triangles, Midpoints, 60 Degrees, Congruence, Rhombus. |
![Geometry problem 1218](../school-college/3/p1218-scalene-equilateral-triangles-midpoint-tutor-1.jpg) |
Geometry Problem 1218
Scalene Triangle, Equilateral Triangles, Midpoints, 60 Degrees, Congruence. |
![Geometry problem 1180](../school-college/2/p1180-triangle-quadrilateral-120-degrees-bisector-1.jpg) |
Geometry Problem 1180
Quadrilateral, 120 Degrees, Diagonals, Perpendicular. |
![Geometry problem 1161](../school-college/2/p1161-scalene-triangle-60-degrees-orthocenter-circumcenter-1.jpg) |
Geometry Problem 1161.
Scalene Triangle, 60 Degrees, Angle, Orthocenter, Circumcenter, Equilateral Triangle, Congruence. |
![Geometry Problem 1120](../school-college/2/p1120-isosceles-right-triangle-equilateral-metric-relation-math-1.jpg) |
Geometry Problem
1120.
Isosceles Right Triangle, 120 Degree, Angle, Equilateral, Metric Relations. |
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Geometry Problem
1062.
Scalene Triangle with an angle of 60 degrees, Euler Line, Orthocenter, Circumcenter, Distance, Congruence, Transversal. |
![Geometry Problem 1000](../school-college/p1000-triangle-120-degree-isosceles-perpendicular-math-metric-relation-1.jpg) |
Geometry Problem
1000.
Scalene Triangle, Isosceles, Angle, 120 Degree, Midpoint, Distance, Equilateral, Congruence, Perpendicular, Metric Relations. |
![Geometry Problem 992](../school-college/p992-triangle-interior-point-20-30-40-50-degree-angle-1.jpg) |
Geometry Problem 992.
Triangle, Interior Point, Angles, 20, 30 , 40, 50 Degree. |
![Geometry Problem 988](../school-college/p988-right-triangle-cevian-30-degrees-triple-angle-1.jpg) |
Geometry Problem 988.
Right Triangle, Cevians, Angles, 30 Degrees, Triple Angle. |
![Geometry Problem 964](../school-college/p964-right-triangle-10-20-30-degrees-angle-cevian-1.jpg) |
Geometry Problem 964.
Right Triangle, Cevians, Angles, 10, 20, 30 Degrees. |
![Geometry Problem 956](../school-college/p956-two-equilateral-triangle-center-midpoint-30-60-90-degrees-1.jpg) |
Geometry Problem 956.
Two Equilateral Triangles, Center, Collinear Points, Midpoint, Right Triangle, 30, 60, 90 Degrees. |
![Geometry Problem 894](../school-college/p894-triangle-incenter-60-degrees-midpoint-parallel-html5-ipad-1.jpg) |
Geometry Problem 894
Triangle, Angle, 60 degrees, Incenter, Midpoint, Parallel Lines.
GeoGebra, HTML5 Animation for Tablets |
![Isometric for iPadd](../ipad/ipad-apps-isometric-hexagon-rhombus-120-degrees-1.jpg) |
iPad Apps:
Isometric.
Hexagons, Rhombus 60-120 degrees. |
![Geometry Problem 892](../school-college/p892-triangle-60-degrees-orthocenter-circumcenter-html5-ipad-1.jpg) |
Geometry Problem 892
Triangle, 60 degrees, Orthocenter, Circumcenter. |
![Geometry Problem 872: Quadrilateral, Triangle, Angle, 30, 90 degrees](../school-college/p872-angle-30-degrees-triangle-quadrilateral-1.jpg) |
Geometry Problem 872
Quadrilateral, Triangle, Angle, 30, 90 degrees. |
![Problem 856: Triangle, Median, Midpoint, Angles, 30, 45 Degrees, Congruence, Auxiliary Lines](../school-college/p857-triangle-median-midpoint-angle-30-degrees-1.jpg) |
Geometry Problem 857
Triangle, Median, Midpoint, Angles, 30, 45 Degrees, Congruence, Auxiliary Lines. |
![Problem 856: Quadrilateral, Diagonals, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines](../school-college/p856-quadrilateral-triangle-angle-30-degrees-diagonal-1.jpg) |
Geometry Problem 856
Quadrilateral, Diagonals, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines. |
![Problem 855: Quadrilateral, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines](../school-college/p855-triangle-angle-30-degrees-auxiliary-lines-1.jpg) |
Geometry Problem 855
Quadrilateral, Triangle, Angles, 30 degrees, Congruence, Auxiliary lines. |
![Quadrilateral, Triangle, Angles, 30 degrees, Congruence](../school-college/p831-quadrilateral-diagonal-midpoint-parallelogram-1.jpg) |
Geometry Problem 831
Quadrilateral, Diagonal, Midpoint, Opposite Angles, Congruence, Parallelogram. |
![Quadrilateral, Triangle, Angles, 30 degrees, Congruence](../school-college/p830-triangle-quadrilateral-30-degree-congruence-1.jpg) |
Geometry Problem 830
Quadrilateral, Triangle, Angles, 30 degrees, Congruence. |
![Triangle, Angles, 30 Degrees](../school-college/p820-triangle-cevian-30-degrees-angle-1.jpg) |
Geometry Problem 820.
Triangle, Cevian, Angles, 30 Degrees. |
![Quadrilateral, Triangle, Angles](../school-college/p819-quadrilateral-triangle-angle-30-degrees-1.jpg) |
Geometry Problem 819.
Quadrilateral, Triangle, Angles, 30 degrees. |
![Equilateral triangles, a common vertex](../school-college/p814-two-equilateral-triangle-vertex-angle-1.jpg) |
Geometry Problem
814.
Two Equilateral Triangles with a common Vertex, Angle. |
![Scalene Triangle with an angle of 60 degrees, Euler Line, Equilateral Triangle](../problem/p761-triangle-60-degrees-euler-line-equilateral-1.jpg) |
Geometry Problem 761
Scalene Triangle with an angle of 60 degrees, Euler Line, Equilateral Triangle. |
![Equilateral triangle, Perimeter](../problem/p754-equilateral-triangle-60-degrees-center-sum-1.jpg) |
Geometry Problem 754.
Equilateral Triangle, Center, Angle, 60 Degrees, Perimeter. |
![Quadrilateral, 120 degrees, Angles](../geometry/p698_triangle_120_degrees_1.jpg) |
Geometry Problem 698.
Quadrilateral, Diagonal, Angle Bisector, Triangle, 120 Degrees. |
![Triangle, 60 Degrees](../problem/p670_triangle_60_degrees_1.jpg) |
Geometry Problem 670.
Triangle, 60 Degrees, Orthocenter, Incenter, Circumcenter, Congruence. |
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