Program CalcGeom count quantity of triangles in a figure.
In the program there is a small graphic editor by means of whom the geometrical figure is drawn.
Screenshot of the program:

For creation of a figure it is necessary to follow the rule:

1. At prompting the cursor on a line it thicken, this implyies that the created point will be on it lines.
   
2. At draw a line through an existing point it is drawn by a ring, this implyies that the line will be lead through this point.
   
3. At concurrence of two points the circle is drawn.
   

For check of these rules, can draw such figure

Should 16 triangles will turn out.

If figures it has been constructed incorrectly it can correspond to such variant:
 at missing a line on a point, or such .

CalcGeom version 0.1.0.43 (~177 KB).