Dot Product of Equilateral Triangle

[mill]

Homework Statement

In an equilateral triangle with sides u, v, w, where they are all unit vectors, find u dot w.

Homework Equations

u dot w = |u||w|cosθ

The Attempt at a Solution

The answer is $\frac {-1} {2}$

cos(120) = -1/2

Elsewhere, I read the statement that since these are already unit vectors then the dot products are simply the angles between them. What does this mean? Does something cancel out the |u||w| in the denominator? Or do |u||w| function to make the dot in terms of unit vectors so they would both be 1 in this case?

Nevermind, got it.

 

[benorin]

Elsewhere, I read the statement that since these are already unit vectors then the dot products are simply the angles between them.

...the dot products are the cosine of the angle between them.