For calculating a cosine one needs a right-angled triangle.

So is the cosine of two vectors the cosine of any right-angled triangle that you can "build" in some way from these vectors ?

# The cosine of two vectors

geometrylinear algebravectors

Skip to content
# The cosine of two vectors

###### Related Question

geometrylinear algebravectors

So is the cosine of two vectors the cosine of any right-angled triangle that you can "build" in some way from these vectors ?

## Best Answer

I assume it refers to the cosine of the angle between these two vectors. It is closely related to the inner product of these two vectors: $$ \vec{a}\cdot \vec{b}=|\vec{a}|\cdot|\vec{b}|\cdot \cos \sphericalangle (\vec{a},\vec{b}) $$