Question

How to I find a? It’s round to the nearest tenth.

Answer 1

a ≈ 21.8

Explanation:

We require the third angle in the triangle

Subtract the sum of the 2 angles from 180

third angle = 180° - (75 + 31.8)° = 180° - 106.8° = 73.2°

Using the Sine rule, that is

`(a)/(sin73.2)` =
`(22)/(sin75)` ( cross- multiply )

a × sin75° = 22 × sin73.2° ( divide both sides by sin75° )

a =
`(22sin73.2)/(sin75)` ≈ 21.8 ( to the nearest tenth )