
Geometry Problems 1100




Open Geometry Problems  Index 

Problem 1.
Triangle, median, angles, 45 degrees. 

Problem 2.
Triangle, angles, 10, 20 , 30 , 80 degrees. 

Problem 3.
Triangle, Angles, 45 degrees, Auxiliary Lines. 

Problem 4.
Quadrilateral, equal sides, angles, 120 degrees. 

Problem 5.
Triangle, cevian, equal segments, angles, cevian. 

Problem 6.
Triangle, cevian, equal segments, and angles. 

Problem 7.
Triangle, cevian, congruence, and angles. 

Problem 8.
Triangles, equal segments, angles, 45 degrees. 

Problem 9.
Triangles, equal segments, angles, 30 degrees. 

Problem 10.
Triangle, cevian, equal segments, angles, 8020 degrees. 

Problem 11.
Right triangle, cevian, angles, degrees. 

Problem 12.
Triangle, cevian, equal segments, angles, degrees. 

Problem 13.
Triangle, cevian, congruence, angles, degrees. 

Problem 14.
Triangle, median, angles, degrees. 

Problem 15.
Triangle, cevian, sum of segments, angles, angle bisector, 30 degrees. 

Problem 16.
Triangle, cevian, perpendicular, angles, angle bisector, degrees. 

Problem 17.
Right triangle, altitude, and angles. 

Problem 18.
Right triangle, cevian, and angles. 

Problem 19.
Isosceles
Right triangle, perpendicular, Excenter, Congruence. 

Problem
20.
Right triangle, altitude, incircles and inradii. 

Problem 21.
Acute triangle, orthocenter, diameter, tangents. 

Problem 22.
Right
triangle, altitudes, incircles and inradii. 

Problem 23.
Right
triangle, altitude, incircles and inradii. 

Problem 24.
Right
triangle, altitude, incircles and inradii. 

Problem 25.
Right
triangle, altitude, incircles and inradius. 

Problem 26.
Right
Triangle, altitude, incircles and inradius. 

Problem 27.
Right
Triangle, incircles and inradius. 

Problem 28.
Right
Triangle, altitude, incircles and inradius. 

Problem 29.
Right
Triangle, altitude, incircle and inradius. Ten conclusions. 

Problem 30.
Right
Triangle, Incircle, Inradius. 

Problem 31.
Right
Triangle, Incircle, Collinears. 

Problem 32.
Triangle, Cevian, Incircles, Tangents. 

Problem 33.
Triangle and quadrilateral. 

Problem 34.
Right
triangle, Cevian, Incircles, Tangents and Inradius. 

Problem 35.
Incenters and Inradii in Cyclic Quadrilateral. 

Problem 36.
Right
triangle, altitude, incircles and inradii. 

Problem 37.
Right
triangle, altitude, incircles, incenters, and orthocenter. 

Problem 38.
Right
triangle, altitude, incircles, incenters, and angles. 

Problem 39.
Triangle, Incircle, Bisector, Cyclic Quadrilateral and angles.
Problem 39 Geometry Help.
Facts you should know for the proposed problem 39. 

Problem 40.
Triangle, Incenter, Excenter, Angles 80, 40, Distances.
Problem 40. Geometry Help.
Suggestions. 

Sangaku Problem 41.
"Mickey
Mouse."
Three circles, tangents, radii. 

Problem 42.
Angles, equal
segments, and triangles, 3060 degrees. 

Problem 43.
Angles equal segments, and triangles, 3060 degrees. 

Problem 44.
Angles and triangles, 3060 degrees. 

Problem 45.
Angles and triangles, 3060 degrees. 

Problem 46.
Triangle, median, and
angles, 30 degrees. 

Problem 47.
Triangle, median, and
angles, 15, 30 degrees. 

Problem 48.
Angles and triangles, 30 degrees. 

Problem 49
Right triangle, cevian,
perpendicular, and angles. 

Problem 50.
Triangle
with Equilateral triangles. 17 Propositions 

Problem 51: Fagnano's Problem
Inscribed Triangle with the Minimum Perimeter. 

Problem 52
Triangle, angles, incircle. 

Problem
53: Angle bisector, circles 

Problem
54: Angle bisector, circles Midpoint of
arc. 

Problem
55: Angle bisector, circles Cyclic
Quadrilateral. 

Problem
56: Angle bisector, circles Parallel
Lines. 

Problem
57: Angle bisector, circles Cyclic
Quadrilateral. 

Problem
58: Right Triangle, Congruence, Perpendiculars. 

Problem
59: Right and Equilateral Triangles, Midpoints.. 

Problem
60: Isosceles triangle. 

Proposed Problem
61:
Triangle, Trisection of Sides, Perimeter. 

Proposed Problem 62:
Square Diagonal, Inscribed Circle, Arc, 90 degrees. 

Proposed Problem 63:
Heptagon Regular, Side and Diagonals. 

Proposed Problem
64: Triangle, Incircle, Transversal. 

Proposed Problem
65: Right Triangle, Mindpoints. 

Proposed Problem
66: Triangle, Excircle, Tangents, Geometric Mean.


Proposed Problem
67: Triangle, Circumcircle, Angles, Cyclic Quadrilateral.


Proposed Problem
68: Triangle, Incircle, Inradius, Tangent, Similarity.


Proposed Problem
69: Square inscribed in a triangle, Similarity.


Proposed Problem
70: Squares inscribed in a triangle, Similarity.


Proposed Problem
71: Cyclic Quadrilateral.
Angles.


Proposed Problem
72: Intersecting Circles.
Cyclic
quadrilateral, Chords, Parallel.


Proposed Problem
73: Three Intersecting Circles. Cyclic
quadrilateral.


Proposed Problem
74: Three Intersecting Circles. Cyclic
quadrilateral, Angles.


Proposed Problem
75: Three Intersecting Circles. Cyclic
quadrilateral, Angles.
Acquire and demonstrate mathematical reasoning ability when solving
problems.


Proposed Problem
76: Area of a Circle. Square,
Circle, Circular Sector.


Proposed Problem
77: Angles of a Circle. Parallel
lines, Cyclic quadrilateral.


Proposed Problem
78: Angles of a Circle.
Perpendicular and parallel
lines, Midpoint, Diameter, Chord, Cyclic quadrilateral, Congruence.


Proposed Problem
79: Triangle.
Similarity, Altitudes, Orthocenter, Incircles, Inradii. 

Proposed Problem
80. Area of a triangle,
side, incircle, inradius. 

Proposed Problem
81. Area of a triangle,
side, inradius, circumradius. 

Proposed Problem
82. Area of the Contact
Triangle,
inradius, circumradius. 

Proposed Problem
83. Area of the Excircle Contact
Triangle, exradius, circumradius. 

Proposed Problem
84. Contact Triangles Areas, Incircle, Excircle, Inradius, Exradius. 

Proposed Problem
85. Contact Triangles Areas, Incircle, Excircle. 

Proposed Problem
86. Intouch and Extouch Triangles, Areas. 

Proposed Problem
87. Area of Quadrilaterals and Midpoints of Diagonals. 

Proposed Problem
88. Triangle and Quadrilateral Areas, Midpoints. 

Proposed Problem
89. Triangles of equal area, Midpoints. 

Proposed Problem
90. Quadrilateral and Triangle
Areas, Midpoints. 

Proposed Problem
91. Similar Triangles, Altitude, Parallel. 

Proposed Problem
92. Similar Triangles, Circumcircles, Circumradii, Parallel. 

Proposed Problem
93. Similar Triangles, Circumcircles, Parallelogram. 

Proposed Problem
94. Similar Triangles, Circumcircles,
Circumradii. 

Proposed Problem
95. Similar Triangles, Inradii,
Parallel. 

Proposed Problem
96. Similar Triangles, Incenters, Parallelogram. 

Proposed Problem
97. Similar Triangles, Areas.


Proposed Problem
98. Quadrilateral Area, Centroid,
Similarity. 

Proposed Problem 99: Circle Area, General Extension to Pythagoras' Theorem.


Proposed Problem
100. Circle Area, Archimedes' Book of Lemmas.


