I've just been trying them. So you have say the left hand a little bit below the shoulder, and the right hand, not so much above the head, but at the level of the head (but still out to the side). The angle from the right hand to the left hand and then down to the feet (taken as one point) forms a right angle. The hypotenuse is from your right hand down to the feet.

Of course, for balancing the exercise, the position of the hands should be interchanged after some number of reps.