699 is closet because as you subtract every number from 750, the smallest answer given is the closest to the number you started with.
(A) a triangle whose angles each measure less than 90°

If the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up (+1).
Answer:
A
Step-by-step explanation:
Associative property:
(a+b)+c=a+(b+c)
(a*b)*c=a*(b*c)