Question

Find the length of side b below using Law of Sines. Give the exact value as an expression and an approximation to the nearest tenth.

Answer 1

b ≈ 7.8

Explanation:

using the law of sines

∠ A = 180° - 105° - 40° = 180° - 145° = 35° , then

`(b)/(sin40)` =
`(7)/(sin35)` ( cross- multiply )

b × sin35° = 7 × sin40° ( divide both sides by sin35° )

b =
`(7sin40)/(sin35)` ≈ 7.8 ( to the nearest tenth )