That is a 30 60 90 right triangle whose hypotenuse =
14 * sq root (3) / 3
In such a triangle the "middle" side =
sq root (3) / 2 * [14 * sq root (3) / 3] = 3 * 14 / 6 =
42 / 6 = 7
The "short" side = (hypotenuse / 2)
"short" side (or "v") = [7 * sq root (3)] / 3
