Answer:option C is the correct answer
Explanation:
Triangle DEF is a right angle triangle.
From the given right angle triangle,
DF represents the hypotenuse of the right angle triangle.
With m∠θ as the reference angle,
EF represents the adjacent side of the right angle triangle.
DE represents the opposite side of the right angle triangle.
To determine Cos ∠θ, we would apply
the cosine trigonometric ratio.
Cos θ = adjacent side/hypotenuse. Therefore,
Cos θ = EF/DF