Answer:∠C = 37° , AB = 26.54 cm , BC= 33.27 cmStep-by-step explanation:Given that in triangle ABC ∠A = 39° AC = 20 cm∠B = 104°∵ sum of all the three angles of triangle = 180°So, ∠C = 180° - ( ∠A + ∠B) ∠C = 180° - (39° + 104°) ∠C = 37°Now Tan 37° = [tex]\frac{AC}{AB}[/tex] Or, AB = [tex]\frac{20}{tan 37°}[/tex] So, AB = 26.54 cmAgain, Sin 37° = [tex]\frac{AC}{BC}[/tex] So, BC = [tex]\frac{20}{sin 37°}[/tex] Or, BC = [tex]\frac{20}{0.601}[/tex] ∴ BC= 33.27 cmHence ∠C = 37° , AB = 26.54 cm , BC= 33.27 cm Answer