Question

What is the length of AC in the given triangle?

Answer 1

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

$\frac{BC}{sin42}$ = $\frac{AC}{sin85}$ , that is

$\frac{85}{sin42}$ = $\frac{AC}{sin85}$ ( cross- multiply )

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

AC = $\frac{85sin85}{sin42}$ ≈ 126.6