To determine the coordinates of point \(B'\) after translating point \(B\) down by 8 units, you would subtract 8 from the y-coordinate of point \(B\).
Since I don't have the specific coordinates of point \(B\), I can't give you the exact answer. However, if you provide the original coordinates of point \(B\), I can calculate \(B'\) for you.
As a general formula, if point \(B\) has coordinates \((x, y)\), then after the translation, the coordinates of point \(B'\) will be \((x, y - 8)\).