Answer
See below.
Work Step by Step
$A=180-102-43=35^\circ$.
Using the law of sines, $\frac{a}{\sin35^\circ}=\frac{21}{\sin102^\circ}\\a=\frac{21\sin35^\circ}{\sin102^\circ}\approx12.4$
$\frac{c}{\sin43^\circ}=\frac{21}{\sin102^\circ}\\c=\frac{21\sin43^\circ}{\sin102^\circ}\approx14.6$
