Using the law of sines, sin80°/3.1 = sin∠QSR/2.4 ∠QSR = sin^-1(2.4sin80°/3.1) ≈ 49.679° ∠SQR = 180° - 80° - 49.679° (angles in a triangle) = 50.321° sin50.321°/RS = sin80°/3.1 RS = (3.1sin50.321°/sin80°) = 2.4 units (nearest tenth) The length of line RS is 2.4 units.
