Answer:
B. 7√3
Step-by-step explanation:
30-60-90 triangles have special side proportions that would be very beneficial to memorize because I guarantee you will use it in the future.
Please see the attached image.
The answer is 7*√3=7√3
-4x +12 -12 = -4 -12
-4x = -16
x = 4
690 because 86 is rounded up to 90