Answer
$50.8^\circ$
Work Step by Step
Using the definition of tangent of the angle B, we have
$$
\tan B=\frac{length \ of \ side\ opposite\ angle\ B}{length \ of \ side\ adjacent\ angle\ B}=\frac{3.21}{2.62}=1.2252
.$$
That is,
$$
\tan B= 1.2252\Longrightarrow B=\tan^{-1} 1.2252=50.8^\circ
.$$
