Online Geometry Theorems and Problems. College, High School

Geometry - Recent Additions

Geometry Problem 1186
Right Triangle, Square, Inscribed Circle, Tangent, Quadrilateral, Area.

Geometry Problem 1185
Similar Rectangles, Four Quadrilaterals, Sum of the Areas, Metric Relations.

Geometry Problem 1184
Right Triangle, Square, Inscribed Circle, Tangent, Concurrent Lines.

Geometry Problem 1183
Parallelogram, Diagonals, Circle, Tangent Line.

Geometry Problem 1182
Two Squares, Four Quadrilaterals, Sum of the Areas, Metric Relations.

Geometry Problem 1181
Cyclic Quadrilateral and Tangential Quadrilateral, Diameter as a Diagonal, Incenter, Circumcenter.

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

Geometry Problem 1179
Triangle, Centroid, Transversal, Sum of Ratios, Sides.

Geometry Problem 1178
Triangle, Angle Bisector, Metric Relations.

Geometry Problem 1177
Triangle, Two Angle Bisectors, Metric Relations.

Geometry Problem 1176
Cyclic Quadrilateral, Diagonals, Six Diameters, Circles, Collinear Points, Concurrent Lines.

Geometry Problem 1175: Six Tangential or Circumscribed Quadrilaterals Theorem

Geometry Problem 1174
Triangle, Quadrilateral, Double, Triple, Angle, Congruence, Excenter, Angle Bisector.

Geometry Problem 1173
Triangle, Cevian, Angle, Congruence, Similarity.

Geometry Problem 1172
Cyclic Quadrilateral, Circle, Secant, Triangle, Similarity, Metric Relations.

Geometry Problem 1171
Area of a Triangle in terms of the three altitude or heights h_a, h_b, h_c.

Geometry Problem 1170
Area of a Triangle in terms of the three sides, a-b-c.

Geometry Problem 1169
Complete Quadrilateral, Orthocenters of the Component Triangles, Collinear Points, Ortholine, Steiner-line, Orthocentric line.

Geometry Problem 1168
Construction of the Inscribed Circle of the Arbelos, Semicircles, Diameter, Circle, Triangle, Circumcircle, Tangent.

Geometry Problem 1167.
Triangle, Circle, Circumcircle, Perpendicular, 90 Degrees, Collinear Points.