Answer
$$\color{blue}{\bf{16\text{ft}}}$$
Work Step by Step
If a roof has a pitch of $\bf\frac{1}{4}$, it $\bf{\text{rises }1ft}$ over a $\bf{\text{run of }4 ft}$
To find the length of the roof that $\bf{\text{rises }4ft}$,
$$\frac{1}{4}=\frac{4}{x}$$
$$\frac{1}{4}*\frac{4}{4}=\frac{4}{\bf{16}}$$
The roof $\bf{\text{rises }4ft}$ over a $\bf{\text{run of }}$$\color{blue}{\bf{16\text{ft}}}$
