Answer:
55°
Step-by-step explanation:

1/2 * 1/4 = 1/8
3/8 * 2/3 = 1/4 same for back left fin
2/5 *1/2 = 1/5
2/3 *1/2 = 1/3
1/4 + 3/4 = 8/8
2/3 +1/6 = 5/6
4/5 +1/5 = 4/4
1/4 +1/5 = 9/20
front/back right fin = 3/8
x+ 1 2/3..... = 4/5
30(30 – x) = 540
distribute
900 -30x = 540
subtract 900 from each side
-30x = -360
divide by -30
x =12
I think 43, but at the same time I might be wrong because I don't know the height.