Answer
See below
Work Step by Step
Assume $=a_{11}b_{11}+a_{12}b_{12}+a_{21}b_{21}+a_{22}b_{22}$
Obtain:
$=2.3+(-1).1+3.(-1)+5.2=12\\
||A||=\sqrt =\sqrt 2.2+(-1).(-1)+3.3+5.5=\sqrt 39\\
||B||=\sqrt =\sqrt 3.3+1.1+(-1).(-1)+2.2=\sqrt 15$
The angle between matrices $A$ and $B$:
$$\cos \theta=\frac{}{{{A}}.||B||}=\frac{12}{\sqrt 39.\sqrt 15}=\frac{12}{\sqrt 585}\\
\theta =\arccos\frac{12}{\sqrt 585}$$