Answer:
37 yd
Explanation:
Use the Law of Sines here. (sin A)/a = (sin B)/b = (sin C)/c
In this particular case, we note that side AB is opposite the 15 degree angle, and that the 10 yd side is opposite the 15 degree angle.
Therefore, we have
BC 10 yd
----------- = ------------
sin 106 sin 15
Solving this yields | BC | = 37 yd (rounded up from 37.14 yd).