Answer:
(d) 7.9 ft
Step-by-step explanation:
The geometry of the problem can be represented by a right triangle whose hypotenuse is the ramp, and the side opposite the given angle is 3 feet. Then the relevant trig relation is ...
Sin = Opposite/Hypotenuse
Solving for Hypotenuse, we find ...
Hypotenuse = Opposite/Sin
ramp length = (3 ft)/sin(22.3°) ≈ 7.9 ft
The ramp is about 7.9 feet long.