Question

The stage used for graduation is 4 feet tall, find the other dimensions (two sides) of the ramp so that it has the maximum angle of elevation specified by the ADA.

Answer 1

Let's draw a diagram of the situation:

The value of thetramp (Slope) is given by:

$slope=\frac{rise}{run}$

Since the slope has to be:

$slope=1:12=\frac{1}{12}$

And:

$rise=4$$\begin{gathered} \frac{1}{12}=\frac{4}{run} \\ run=48 \end{gathered}$

So, the other dimension is 48ft. And the angle of elevation is given by:

$\begin{gathered} \theta=tan^{-1}(\frac{4}{48}) \\ \theta\approx4.76^{\circ} \end{gathered}$