Answer:
θ = 36.9°
Explanation:
Trigonometric ratios in a right triangle will be,
Sinθ =
=

Cosθ =
=

Tanθ =
=

In the picture attached,
Given sides are,
AB = 5 and BC = 4
Therefore, to find the given angle θ only Cosine will be applicable.
Cos θ =

=

θ =

θ = 36.87°
θ ≈ 36.9°