Triangles: Theorems and Problems 32

Proposed Problem 101.Equilateral Triangle, Pythagorean Theorem, Angles.

Triangle and Squares Theorem 1: with Interactive Geometry Software
Step-by-Step construction, Manipulation, and animation.

Bottema's Theorem: Triangle and Squares with Interactive Geometry Software
Step-by-Step construction, Manipulation, and animation.

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

Complete Quadrilateral: Ortholine-Steiner Line.
Using TracenPoche Dynamic Software
Step-by-Step construction, Manipulation, and animation

Proposed Problem 97. Similar Triangles, Areas.

Proposed Problem 96. Similar Triangles, Incenters, Parallelogram.

Proposed Problem 95. Similar Triangles, Inradii, Parallel.

Proposed Problem 94. Similar Triangles, Circumcircles, Circumradii.

Proposed Problem 93. Similar Triangles, Circumcircles, Parallelogram.

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

Proposed Problem 91. Similar Triangles, Altitude, Parallel.

Gergonne's Theorem: Triangle and Concurrent Cevians.

Proposed Problem 90. Quadrilateral and Triangle Areas, Midpoints.

Proposed Problem 89. Triangles of equal area, Midpoints.

Proposed Problem 88. Triangle and Quadrilateral Areas, Midpoints.