The 30-60-90 ratio is a special right triangle that always has angles with measures: 30º, 60º, and 90º. Its side lengths have also the same relationship one with another.
For any 30-60-90 the ratio is as follows:
The side opposite to the 30º angle has length: z
The side opposite to the 60º angle has a length z√3
The side opposite to the 90º angle has a length: 2z
Following these ratios, you can determine the side lengths of the triangle.
The measure opposite to the 60º angle is z√3 = 9√3 → From this we can determine the value of z, which is z=9
Once we know the value of z, we can calculate the values of the sides opposite to the other angles.
The side opposite to the 30º angle is y= z= 9
The side opposite to the 90º angle is x= 2z= 2*9 = 18
