Online Geometry Theorems and Problems. College, High School

Geometry - Recent Additions

Apollonius of Perga, Theorems and Problems
Index 

Geometry Problem 1231
Triangle, Orthocenter, Incenter, Circumcenter, Angle Bisector, Center, Circle.

Orthic Axis Index

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

Geometry Problem 1229
Three Tangent Circles, Common Tangent Line, 3-4-5 Right Triangle.

Geometry Problem 1228
Three Tangent Circles, Midpoint, Major Arc, Common Tangent Line, Square.

Geometry Problem 1227
Triangle, Circumcircle, Angle Bisector, Concyclic Points, Cyclic Quadrilateral.

Geometry Problem 1226
Quadrilateral, Squares, Centers, Midpoints, Congruence.

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

Geometry Problem 1224
Triangle, Parallel to the Sides.

Geometry Problem 1223
Circle, Parallel Chords.

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

Geometry Problem 1221
Equilateral Triangles, Midpoints, 60 Degrees, Congruence.

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

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

Geometry Problem 1218
Triangle, Equilateral Triangles, Midpoints.