Question

What is the length of AC in the given triangle?

Answer 1

A

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

`(BC)/(sin42)` =
`(AC)/(sin85)` , that is

`(85)/(sin42)` =
`(AC)/(sin85)` ( cross- multiply )

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

AC =
`(85sin85)/(sin42)` ≈ 126.6