Answer
So $HL= 6$
$HK = 12$
$MK= 6$
Work Step by Step
In $\triangle HKL$
$\angle HKL = 30^{\circ}$
So $ \angle LHK =60^{\circ}$
now By Theorem 5.5.2/ (30-60-90 Theorem)
$LK= 6\sqrt 3 $ given
So $HL= 6$
$HK = 12$
$MK= HK/2 = 12/2= 6$