Answer:
3.6cm
Step-by-step explanation:
the points lie in order like this
A.....B.....C
we know that A......B......C total spans 4cm (or 40mm)
we know that A......B spans 4mm
we need to know the length of B......C
B......C = A.......B.......C - A.....B = 40mm - 4mm = 36mm = 3.6cm
