Answer:
∠ A ≈ 43.1°
Step-by-step explanation:
Using the Sine rule in Δ ABC , that is
[tex]\frac{a}{sinA}[/tex] = [tex]\frac{c}{sinC}[/tex] , substitute values
[tex]\frac{20}{sinA}[/tex] = [tex]\frac{29}{sin82}[/tex] ( cross- multiply )
29 × sinA = 20 × sin82 ( divide both sides by 29 )
sinA = [tex]\frac{20sin82}{29}[/tex] , thus
∠ A = [tex]sin^{-1}[/tex] ([tex]\frac{20sin82}{29}[/tex] ) ≈ 43.1° ( to 1 dec. place )
