Recall the definition of the dot product:
A → ⋅ B → = | | A → | | | | B → | | c o s ( θ ) {\displaystyle {\overrightarrow {A}}\cdot {\overrightarrow {B}}=||{\overrightarrow {A}}||\ ||{\overrightarrow {B}}||cos(\theta )}
What does it tell you about two intersecting vectors?
