it is given that,
the given ramp is a right angle ramp withe the angle 8 degrees,
it is given that
the ramp is used to access an 18-inch step to a door
so, the perpendicular of the ramp is P = 18 in
the length of the ramp is = hypotenuse,
[tex]\sin \theta=\frac{\text{perpendicular}}{\text{hypotenuse}}[/tex][tex]\begin{gathered} \sin 8=\frac{18}{\text{hypotenuse}} \\ \text{hypotenuse = }\frac{18}{0.139} \\ \text{hypotenuse = 129.49} \end{gathered}[/tex]
so, the length of the ramp is approx 129 in.
thus, the correct answer is option D
