Geometric Constructions 11
triangle moves on a plane so that two vertices move along two fixed perpendicular
lines. How does the third vertex move?
the above situation to two fixed lines not necessarily perpendicular to
Theorem: the centers L, M, N of the three equilateral triangles
built outwards on the sides BC, CA, AB of an arbitrary triangle DABC
are the vertices of an equilateral triangle. The same is true of the centers
of the three inward equilateral triangles.
interesting properties associated with the Torricelli's configuration.
the properties of the figure consisting of a quadrilateral together with
the four squares erected outwardly on the sides.
a figure to illustrate the following cases of indeterminate forms
all at the same time: