On Oct 8, 3:38*pm, Papa3 wrote:
1.4.6b. TRIANGLE FLIGHT A CLOSED COURSE having three LEGS. The
geometry may be either:
(i) A triangle having two TURN POINTS, or
(ii) A triangle having three TURN POINTS independent of the position
of the START/FINISH POINT. The distance is given by the sum of
the LEGS of the triangle formed by the TURN POINTS. The minimum
OFFICIAL DISTANCE (1.3.9) is 300 kilometres.
For triangle record COURSES of 750 km or more, the length of each LEG
shall be 25% to
45% of the OFFICIAL DISTANCE. For record COURSES shorter than 750 km,
no LEG may
have a length of less than 28% of the OFFICIAL DISTANCE.

Whoo boy. *This one sounds complicated, but it is easier if you break
it down.

The geometry prevents you from having a very "flat" triangle where you
basically fly along the ridge and bounce out a few miles to make a
triangle with one very LOOONG leg and two other legs that are only
half as long.

A 28% rule is much more extreme than that It rules out, for example,
almost all right angle triangles, unless the two shorter legs are very
close to being equal length (which makes them 29.3% of the total).
Even a classic 3,4,5 right angle triangle is illegal, as the shorter
leg is only 25% of the total. An example of the most uneven right
angle triangle that qualifies for the 28% rule is 252,275,373.

Or, to put it another way: none of the interior angles can ever be
bigger than 103.5 degrees (the largest angle in a 28,28,44 triangle --
the other two are 38.2 degrees).

That is really very different to an out and back -- on a 500 km
triangle using a straight ridge for a 44% leg, the center turn point
is at least 87 km from the ridge!