Question 1156397
<pre>
{{{drawing(400,1840/9,-1,8,-1,3.6,

locate(3.4,0,7), locate(6.2,1.6,3),  locate(3,1.85,6),

triangle(0,0,7,0,5.428571429,2.55550626) )}}}

just ONE!  A triangle is the only rigid polygon.  You can
turn it over, and turn it at any angle, but the triangle
will always stay the same shape.

{{{drawing(300,2400/7,-1,6,-1,7,

locate(1.57,3.44,7), locate(3,2,6),  locate(4.35,4.8,3),

triangle(0,0,3.5,6.062177826,4.927419055,3.423527633) )}}}

Edwin</pre>