To solve for the width of the trampoline, we can use the quadratic equation given:
\[ w^2 + 6w - 112 = 0 \]
We can use the quadratic formula to find the roots of the equation:
\[ w = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]
In this equation, \(a = 1\), \(b = 6\), and \(c = -112\). Plugging in these values:
- Calculate the discriminant:
\[ b^2 - 4ac = 6^2 - 4(1)(-112) = 36 + 448 = 484 \]
- Calculate the square root of the discriminant:
\[ \sqrt{484} = 22 \]
- Now plug the discriminant back into the quadratic formula:
\[ w = \frac{-6 \pm 22}{2(1)} = \frac{-6 \pm 22}{2} \]
This gives us two possible solutions:
\[ w = \frac{16}{2} = 8 \quad \text{and} \quad w = \frac{-28}{2} = -14 \]
Since the width cannot be negative, we take \(w = 8\).
Thus, the width of the trampoline is:
\[ \boxed{8 \text{ ft}} \]