Triangle ABC is:

Point A 0,0
Point B 6,4
Point C 9,0

If it is translated down by 8 units, what is point B’s coordinates at?

After being translated down by 8 units, the y-coordinate of point B will decrease by 8.

Point B's original coordinates are (6, 4).

After the translation, point B's coordinates will be:
x-coordinate: 6
y-coordinate: 4 - 8 = -4

Therefore, point B's coordinates after being translated down by 8 units will be (6, -4).