Answer:
A, 3 root 3
Step-by-step explanation:
The triangle is a 30-60-90 Triangle meaning that the shortest side can be multiplied by 2 to get the hypotenuse or the slanted/longest side.
The second longest side of this triangle will always be the shortest side times root 3. Use the chart as a reference.
3√3
Angle ratio = 30 : 60 : 90
Side ratio = a : a√3 = 2a
Side opposite to 90° = 2a
2a = 6
a = 6/2
a = 3
Side opposite to 60° = a√3
x = a√3 =3√3
