Anyone see a problem with this geometrical method?
No problem,
Mises, but there are an infinite number of solutions to it.
To
buttrick and the others that are still having difficulties understanding how, if the plane was at a higher speed, the crash location would be closer to Malaysia:
If the plane travelled faster, then it would have achieved less range. This is a well known fact of aerodynamics. The laws governing this reality are the same as those for your car. Try driving somewhere at 100 until you run out of fuel. Then, try again at a speed of 80. You will get further along the road at 80.
So, at the higher speed, the plane covered less distance. Therefore, the crash point is closer to Malaysia than originally calculated. So the crash point would still be on the 40 degree arc, but at a point further up - which is a point to the northeast of the original area - which is exactly how they have moved the search area.