Question

If you know that cosine of the obtuse supplementary angle -0.3456 what can you determine about the acute angle

Answer 1

69.8°

Explanation:

Since cosФ = -0.3456

Ф = cos⁻¹(-0.3456)

Ф = 110.2°

Since the angles are supplementary, let the acute angle be x

So, x + 110.2° = 180°

x = 180° - 110.2°

x = 69.8°