There is a 30 ft difference how can you not tell
We have two right triangles and three different rectangles.
The formula of an area of a right triangle:

l₁, l₂ - legs
We have l₁ = 20cm and l₂ = 21cm. Substitute:

The formula of an area of a rectangle:

l - length
w - width
We have:
rectangle #1: l = 22cm, w = 29cm

rectangle #2: l = 22cm, w = 21cm

rectangle #3: l = 22cm, w = 20cm

The total Surface Area of the triangular prism:

Answer:
2+n=-6
Step-by-step explanation:
To simplify n
n=-8
Answer:
I don't know which letter answer it is because it is unclear in the question, but the answer is:
28/100 for the fraction
0.28 for the decimal