Answer:
https://youtu.be/wOH_gVtidns
I recorded a video of myself explaining it hope it helps ;)
Step-by-step explanation:
It's 90 because the shape is a square.
See how all the sides are parallel.
L = 2w
perimeter = 2l + 2w = 6w
6w = 54
w = 9
7 * 6 * 5 * 4 * 3 * 2 * 1
Which will give us 5040.
It is either in the ones place or the hundred millions place
