Triangles: Theorems and Problems 27

Proposed Problem 154. Triangle, Inradius, Circumradius, Chord.  

Proposed Problem 147. Quadrilateral, Area, Midpoints, Triangle.

Proposed Problem 146. Varignon's Theorem: Quadrilateral, Midpoints, Parallelogram, Area, Perimeter.

Proposed Problem 145. Four Triangles, Incircle, Tangent and Parallel to Side, Incenters, Circumcenters.  

Proposed Problem 144. Four Triangles, Incircle, Tangent and Parallel to Side, Inradii.  

Proposed Problem 143. Four Triangles, Incircle, Tangent and Parallel to Side, Circumradii.  

Proposed Problem 142. Four Triangles, Incircle, Tangent and Parallel to Side, Areas.  

Proposed Problem 141. Triangle, Incircle, Tangent , Parallel, Perimeters.  

Proposed Problem 140. Triangle, Excircle, Tangent, Semiperimeter.  

Proposed Problem 139. Triangle Area, Orthic Triangle, Semiperimeter, Circumradius.  

Proposed Problem 138. Nagel's Theorem, Orthic Triangle, Altitudes, Circumradius, Perpendicular.