Respuesta :

Answer:

A

Step-by-step explanation:

We require to find ∠ A

Subtract the sum of the given angles from 180

∠ A = 180° - (85 + 53)° = 180° - 138° = 42°

Using the Sine rule in Δ ABC, that is

[tex]\frac{BC}{sin42}[/tex] = [tex]\frac{AC}{sin85}[/tex] , that is

[tex]\frac{85}{sin42}[/tex] = [tex]\frac{AC}{sin85}[/tex] ( cross- multiply )

AC × sin42° = 85 × sin85° ( divide both sides by sin42° )

AC = [tex]\frac{85sin85}{sin42}[/tex] ≈ 126.6