+128408 Use Law of Sines to find angle C
sin C / 8 = sin150 / (7sqrt (3))
sin C = 8 sin (150) / (7sqrt (3))
sin C = 8 (1/2) / (7sqrt (3))
sin C = 4 / (7sqrt (3) )
arcsin C = [ 4 / (7sqrt (3)) ] ≈ 19.3°
Angle B= 180 - 150 - 19.3 ≈ 10.7°
Using the Law of sines once more
AB /sin B = BC / sin A
AB / sin (10.7) = 7sqrt (3) / sin (150)
AB = sin (10.7) * 7sqrt (3) / (1/2)
AB = sin (10.7) * 14 sqrt (3) ≈ 4.5
