Answer:
None of these
Explanation:
The two cases are for trigonometry special angles.
The cosine of an angle is given as the adjacent side length divided by the hypotenuse side length
Cos ∅ = A/H
1. The case of 45°,45°,90°
Cos x = 1 /√2
2. The case of 30°, 60° ,90°
Cos x = 1/2 or √3/2