Answer:
θ ≈ 39.1°
Explanation:
Applying the law of sines in Δ ABC
=
=

where a, b, c are the sides opposite ∠ A , ∠ B, ∠ C
we are given
b = 56.3 , c = 80.2 , ∠ C = 64 , then using
=
( substitute values )
=
( cross- multiply )
80.2 × sinθ = 56.3 × sin64° ( divide both sides by 80.2 )
sinθ =
, then
θ =
(
) ≈ 39.1° ( to 1 decimal place )