Answer
$A =85^\circ$
$a \approx14.56$,
$c \approx14.12$
Work Step by Step
1. Find the third angle $A=(180-20-75)=85^\circ$
2. Use the Law of Sines, we have $\frac{a}{sin85^\circ}=\frac{c}{sin75^\circ}=\frac{5}{sin20^\circ}$
3. thus $a=\frac{5sin85^\circ}{sin20^\circ}\approx14.56$, $c=\frac{5sin75^\circ}{sin20^\circ}\approx14.12$
