You use the formula below...,
Angle theta = cos^-1 [scalar product of the two vectors ÷ multiplication of their moduli]
For example...the angle between
(2i + 3j) and (4i + 5j)
Angle theta = cos^-1 [( 2(4) + 3(5))÷((square root of (2^2 + 3^2))×(square root of (4^2 + 5^2))
Angle theta = cos^-1 [ 23 ÷ ((square root of(13)) × (square root of (41)]
Angle theta = 5°
