So to find the answer we need to know the area of the deck by splitting each individual part into smaller shapes.
So for the rectangle up top we have: 50ft
Then for the triangle: 12.5ft
Then another rectangle above the triangle which is: 50 ft
Then the biggest rectangle is: 375ft
We would add this all together.
50+50+375+12.5=487.5
So one gallon costs $34 and covers 200 ft
So 487.5/200=2.437->multiply it by 34 and get 82.8 or $83
Your answer is $83