The "upturned tip" dihedral certainly appears to have the advantage.
At this point in Book VI it is customary to introduce the dihedral angle.
The word "dihedral" is from the Greek, di- meaning "two," and hedra meaning "seat."
It is a monoplane of the dihedral type, with a main plane on each side of the center.
The crystals of citric acid are oblique prisms with four faces, terminated by dihedral summits, inclined at acute angles.
The reason is that the flexible covering will be bowed back by the wind, forming an approximate "dihedral angle."
This feature is still to be found in many aeroplanes to-day and has come to be known as the 'dihedral.'
The locus of a point equidistant from the faces of a dihedral angle is the plane bisecting the angle.
In determining the center of gravity, the bird was frozen in the soaring position, its wings making a dihedral angle of 150.