Length x width = A
therefore length = A/width
8712/88 = length
length = 99m
Answer:

(If that closed circle is an open circle, please let me know because that means something totally different)
Step-by-step explanation:
I think you are given:
and that you are asked to find:

That operation means multiplication. (Let me know if is an open circle because that means something difference).

Distribute:

Reorder a little (commutative property):

Search google, or youtube, there are many videos that can help you :)