there is no real solution. really i just simplified. if you wanted a real answer y would have to be giving. if not then this is all the question is asking. for you to simplify
<span>On the one hand we know that sin(30) = 1/2. On the other hand we know that sin(A) = a/c. From these two relations we obtain that 1/2 = a/c <=> 1/2 = a/12 <=> a = 12*1/2 <=> a = 6. So the answer is D. 6cm.</span>