Any help would be greatly appreciated :)

Sorry to burst your bubble but this is a Math forum. If you want help in this, try something like brainly.com

Since the sum of the angles in this are supposed to be 180o and that one of the angles is 90o, we can use a bit of algebra to find the answer.

4s + 8 = 180 - (54 + 90)

4s + 8 = 180 -144

4s + 8 = 36

4s = 28

s = 7