It would be 36 units, why is that not an answer choice?
Acute
Angle ∠ A = α = 25.385° = 25°23'6″ = 0.443 rad
Angle ∠ B = β = 73.004° = 73°14″ = 1.274 rad
Angle ∠ C = γ = 81.611° = 81°36'41″ = 1.424 rad
X^4 - x^2 + 9 - (x^3 + 3x^2 + 12) =
x^4 - x^3 - 4x^2 - 3