PQ // BC
then
Angle P = Angle B, A is common angle the two triangles are similar
AP/AB = AQ/AC
8/18 = 12/ AC
AC = 12 * 18/8 = 27 (your ans: D)
AQ + QC = AC
QC = AC - AQ = 27 - 12 = 15 (if it was required)
tan60 = y/8
y = s tan60 = 8sqrt(3) (B)
Next time, post each question separately.
The triangles are not the same size so a dilation made the original one smaller and a translation moved it to map ABC to A'B'C'.
I think the correct answer is C. Since a=πr², in order to get the area to become 1/4 of what it was previously, the radius needs to be cut in half to make the divide that side by 4. a=π(r/2)²=πr²/4 and will therefore multiply the area by 1/4.