Answer:
10.20°
Step-by-step explanation:
Given that:
Grade = 18% ; rise = 18ft
For every 100 feets, plane roses 18%
The question can be solved using Pythagoras rule :
Tangent θ = opposite / Adjacent
Tan θ = 18 / 100
Tan θ = 0.18
θ = tan^-1(0.18)
θ = 10.203973
θ = 10.20°