F(x) = x² + 4x - 12
x = -b/2a
x = -(4)/2(1)
x = -4/2
x = 2
f(x) = x² + 4x - 12
f(2) = (2)² + 4(2) - 12
f(2) = 4 + 8 - 12
f(2) = 12 - 12
f(2) = 0
The vertex of the function is (2,0).

Step-by-step explanation:
1) Subtract 2 from both sides.

2) Simplify 6 - 2 to 4.

3) Divide both sides by 2.

4) Simplify 4/2 to 2.

Therefor, the answer is, d >2.
Look at the picture......
1 feet = 30.5 centimetres
1 feet² = (30.5)² centimetres²
2250 feet² = 2250 × 30.5² = 2093062.5 centimeters²
D'(-3,-4)
E'(-3,-10)
F'(3,-6)