triangle, parallelograms, incidence
- Dick Lane
Use the following steps to construct a figure.
- Pick non-collinear points A, B, C [note: you can move any of these points]
- Pick point M inside triangle A.B.C [note: you can move point M]
- Locate point M_c such that quadrilateral A.M.B.M_c is a parallelogram.
- Locate point M_b such that quadrilateral A.M.C.M_b is a parallelogram.
- Locate point M_a such that quadrilateral B.M.C.M_a is a parallelogram.
The Generalized Conception in Problem Solving, A. V. Brushlinskii, Analyses of Reasoning Processes, pages 45--55