<h3>Answer: 20.3</h3>
Work Shown:
tan(angle) = opposite/adjacent
tan(B) = AC/AB
tan(67) = x/8.6
8.6*tan(67) = x
x = 8.6*tan(67)
x = 20.2603303460843 ... make sure your calculator is in degree mode
x = 20.3 .... rounding to 3 significant figures
see diagram below