Answer:
y = 12
Explanation:
Looking at the large triangle
tan 30 = opposite / adjacent
tan 30 = 4 sqrt(3)/ y
Multiply each side by y
y tan 30 = 4 sqrt (3)
We know tan 30 = sqrt(3)/3
y * sqrt(3)/3 = 4 sqrt(3)
Multiply each side by 3/ sqrt(3) to isolate y
y * sqrt(3)/3 * 3/ sqrt(3) = 4 sqrt(3) * 3 /sqrt(3)
y = 12