The angle opposite the longest side of the triangle is 90 degrees
Step-by-step explanation
A 30-60-90 triangle is a right triangle with angle measures of 30º, 60º, and 90º (the right angle). Because the angles are always in that ratio, the sides are also always in the same ratio to each other.
The triangle is shown below:
The angle opposite the longest side is usually the longest side as shown from the diagram.