Answer
$a= 0.4832\ m$, $b= 0.3934\ m$, and $A= 50^\circ51'$
Work Step by Step
Given $B=39^\circ09', c=0.6231\ m$, we have $a=c\ cosB=0.6231cos(39^\circ09')\approx0.4832\ m$, $b=c\ sinB=0.6231sin(39^\circ09')\approx0.3934\ m$, and $A=90^\circ-39^\circ09'=50^\circ51'$
