Question

Can someone help and explain

Answer 1

∠ A ≈ 43.1°

Explanation:

Using the Sine rule in Δ ABC , that is

`(a)/(sinA)` =
`(c)/(sinC)` , substitute values

`(20)/(sinA)` =
`(29)/(sin82)` ( cross- multiply )

29 × sinA = 20 × sin82 ( divide both sides by 29 )

sinA =
`(20sin82)/(29)` , thus

∠ A =
`sin^(-1)` (
`(20sin82)/(29)` ) ≈ 43.1° ( to 1 dec. place )