18.87 inches the cube root of 6720
The opposite of 3.78 is -3.78
I might be wrong but i believe you can make more than one with those 3 angles. the 120 and 40 can make one and if angled right can make 2 and the 10 deg on one of the other angles lines would give you a 3rd.
Let's take as example a linear function of the form:
y = kx.
Where,
k is the constant of proportionality.
Therefore, the proportionality constant is the point:
(x, kx)
Generically it is always the point:
(x, k * f (x))
Where, f (x) is a function proportional to x.
answer:
The constant of proportionality is always the point (x, k * f (x)), where k is the constant of proportionality.