College Algebra (11th Edition)

We know that the pitch (the slope) is: $\displaystyle \frac{1}{4}$. If the vertical rise is $4$ feet, we can find the horizontal length: $slope=\frac{rise}{run}=\frac{4}{x}=\frac{1}{4}$ $\frac{4}{x}=\frac{1}{4}$ $4*4=x$ $x=16$ So the horizontal length must be 16 feet.