Answer:
36.87°
Explanation:
Given the right angle triangle :
To obtain the value of Cosθ ; we use the trigonometric relation :
Cosθ = Adjacent / Hypotenus
The adjacent angle isn't given :
Opposite = 9 ; hypotenus = 15
Adjacent = √(hypotenus ² + opposite ²)
Adjacent = √(15² - 9²)
Adjacent = √(225 -81)
Adjacent = √144 = 12
Hence,
Cos θ = 12/15
θ = Cos^-1(12/15)
θ = 36.87°