Recent Additions 6, Theorems and Problems, Plane Geometry

Geometry Theorems and Problems - Recent Additions (Page 6 of 15)

Problem 476.
Triangle, Circumcenter, Circumcircle, Angles.

Problem 475.
Tangent Circles, Secant, Tangent, Parallel.

Geometry Problems 41 - 50.
Triangle, Sangaku, Quadrilateral, Circle, 30-60 Degrees.

Problem 474.
Parallelogram, Diagonal, Circle, Vertex.

Problem 473.
Triangle, Parallel, Side, Parallelogram, Area, Similarity.

Problem 472.
Triangle, Parallel, Side, Parallelogram, Area, Similarity.

Geometry Problems 21 - 30.
Right triangle, Altitude, Incircle and inradius, Congruence, Circle.

Problem 471.
Triangle, Parallel, Side, Concurrency, Area, Similarity.

Geometry Problems 11 - 20.
Angle, Angle bisector, Triangle, Altitude, Median, Congruence, Cevian, Circle, Excircle, Excenter, Inradius, Exradius

Problem 470.
Triangle, Parallel, Side, Parallelogram, Area, Similarity.

Geometry Problems 1 - 10.
Angle, Triangle, Quadrilateral, Congruence, 20, 30, 45, 60, 80, 120 degrees, Median, Auxiliary lines.

Proposed Problem 469.
Isosceles triangle, Midpoint, Transversal, Congruence.

Proposed Problem 468.
Circle, Chord, Midpoint, Congruence, Angle.

Proposed Problem 467.
Concentric Circles, Chord, Tangent, Congruence, Measurement.

Proposed Problem 466.
Concentric Circles, Secant, Congruence, Measurement.

Proposed Problem 465.
Square, Arc, Angle, 90 Degrees, Measurement.

Napoleon's theorems and problems, Index.

Proposed Problem 464.
Square, Arcs, Center, Angle, 90 Degrees, 120 Degrees.

Concentric Circles. Index.
Theorems and Problems. 

Concentric Circles Definition.

Proposed Problem 463.
Three Concentric Circles, Secant, Tangent, Triangle, Area.

Proposed Problem 462.
Square, Arcs, 90 Degrees, Circle, Tangent, Radius, Measurement.

Proposed Problem 461.
Three Circles, Tangent, Right Angle, Center, Distance, Measurement.

Proposed Problem 460.
Circle, Tangent, Perpendicular, Radius, Distance, Measurement.

Proposed Problem 459.
Right triangle, Squares, Distance, Measurement.

Proposed Problem 458.
Square, Semicircle, Circular Sector, Internal Common Tangent, Measurement.

Proposed Problem 457.
Triangle, First Brocard Point, Congruent angles, Circle, Circumradius.

Proposed Problem 456.
Three tangent circles, Center, Chord, Secant, Collinear.

Proposed Problem 455.
Rhombus, Inscribed Circle, Angle, Chord, 45 Degrees.

Proposed Problem 454.
Triangle, Incircle, Inradius, Tangent, Circle, Radius.

Proposed Problem 453.
Intersecting Circles, Tangent, Circular Segment, Congruence, Area.

Triangle Centers, Visual Index.

Fermat Point.
 

Vecten Outer Point.
 

Proposed Problem 452.
Triangle, Circle, Tangent, Proportional Segments.

Proposed Problem 451.
Triangle, Median, Congruence, Proportional Segments.

Proposed Problem 450.
Triangle, Median, Cevian, Congruence, Proportional Segments.

Proposed Problem 449.
Congruent Tangent Circles, Diameter, Sagitta, Arc, Perpendicular, Chord.

Proposed Problem 448.
Tangent Circles, Diameter, Perpendicular, Chord.

Proposed Problem 447.
Complete Quadrilateral, Inradii, Exradii, Sides.

Complete Quadrilateral Index.
 

Proposed Problem 446.
Quadrilateral Area, Dividing the sides into 5 equal parts.

Proposed Problem 445.
Three Tangent Circles, Tangency Points, Circumradius.

Proposed Problem 444.
Internally Tangent circles, Secant line, Chords, Angles, Congruence.

Proposed Problem 443.
Overlapping, Intersecting Circles, Common Chord, Secant line, Tangent line, Angles.

Proposed Problem 442.
Triangle, Median, Cevian, Transversal, Congruent Angles.

Proposed Problem 441.
Quadrilateral, Triangle, Area, Proportion, Measurement, Similarity.

Proposed Problem 440.
Triangle, Incircle, Incenter, Angle Bisector, Tangency Points, Circle, Angles.

Marion Walter's Theorem and Related Topics: Index

Proposed Problem 439.
Isosceles triangle, Cevian, Incenter, Angles, Circle.

Proposed Problem 438.
Tangent Circles, Diameter, Chord, Perpendicular, Congruence, Measurement, Parallel lines.

Proposed Problem 437.
Tangent Circles, Diameter, Chord, Perpendicular, Congruence, Measurement.

Proposed Problem 436.
Tangent Circles, Diameter, Chord, Perpendicular, Congruence, Measurement.

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

Distances between Triangle Centers Index.

Proposed Problem 435.
Triangle, Incircle, Inradius, Congruent circles, tangent, Measurement.

Proposed Problem 434.
Quadrilateral, Transversal, Ratio, Measurement, Similarity.

Proposed Problem 433.
Quadrilateral, Triangle, Area, Proportion, Measurement, Similarity.

Proposed Problem 432.
Trapezoid, Parallel, Measurement, Similarity, Transversal.

Proposed Problem 431.
Quadrilateral, Midpoints of Diagonals, Transversal.

Transversal Lines.

Proposed Problem 430.
Circumscribed and Inscribed Regular Pentagon, Perpendicular, Areas.

Obtuse Angle. Theorems and Problems.

Isosceles Triangle 80-20-80. Index

Proposed Problem 429.
Circumscribed and Inscribed Regular Pentagon, Perpendicular, Measurement.

Proposed Problem 428.
Quadrant of a circle, Square, Angle bisector, Measurement.

Euclid's Elements Book I, Proposition 8: (Side-Side-Side SSS Congruence)

Euclid's Elements Book I, Proposition 7
Given two straight lines constructed on a straight line (from its extremities) and meeting in a point,...

Proposed Problem 427.
Triangle, Two Altitudes, Square of a Side.