Θ = arcsin ( .7 4.2 ) ≈ 10 ∘ Explanation: We view the ramp as a right triangle. The hypotenuse is 4.2 and the vertical side .7, which is opposite the angle θ we seek. sin θ = .7 4.2 = 1 6 I'm going to finish the problem but I'll note if we were actually building the ramp we don't need to know the angle; this sine is sufficient. θ = arcsin ( 1 6 ) θ ≈ 10 ∘ which I think is a pretty steep ramp for a wheelchair. There will be another inverse sine that is the supplementary angle, around 170 ∘ , but we can rule that out as a value for a ramp wedge angle.