What is the length of BC¯¯¯¯¯ ? Round to the nearest tenth of a unit. 3.5 units 4.9 units 8.6 units 15.0 units Line segment on a coordinate grid. Segment begins at point B whose coordinates are begin ordered pair 1 comma 6 end ordered pair and ends at point C whose coordinates are begin order pair 8 comma 1 end ordered pair.