Answer:
72°
Step-by-step explanation:
Given two vectors a and b, The vector i+3j will form a right angled triangle with the x-axis (i.e the horizontal axis).
The opposite side of the triangle on the Cartesian plane will be 3units along the y axis while the adjacent will be 1 unit along the x axis.
The angle between thus two vectors is expressed as tan (theta) = opp/adj
tantheta = 3/1
theta = tan^-1(3)
Theta = 71.57° ≈ 72° to nearest degree
