Question

Analyze the diagram below and complete the instructions that follow.

Answer 1

Observe that this is a equilateral triangle, meaning that all sides are the same.
So y = 18 eliminates A and C.
Now we have to decide whether x = 18, or x = 9 sqrt(3).
But this is easy to see, since there's no way that x = y in a right triangle. So, without any calculation, we can say x = 9 sqrt(3) is the correct answer.

Answer 2

Since this is a 30 60 90 triangle you can use its properties to help. So we would divide 18/2 to get just one triangle base. Then use the 9sqrt3 to get x and 2x=18 to get y. So the answer is D