The Law of Sines

An oblique triangle is any triangle that does not have a right angle. An oblique triangle is either an acute triangle, having three acute angles (less than 90°), or an obtuse triangle, having one obtuse angle (between 90° and 180°). In any triangle, with sides a, b, c and opposite angles α, β, γ respectively: sin α / a = sin β / b = sin γ / c, or a / sin α = b / sin β = c / sin γ Chapters 0:00 Oblique triangles: acute and obtuse 0:32 Remember that 1:10 The Law of Sines 1:39 Data required for solving oblique triangles: the four cases 2:24 Case (I): one side and two angles are known (ASA or SAA) 2:44 Example (SAA): α = 32°, β = 81.8°, a = 42.9 cm 4:03 Example (ASA): α = 35°, β = 15°, c = 5 cm 5:07 Example (AAS): α = 45°, β = 60°, a = 10 m 6:08 Example (ASA): α = 46°, b = 200 cm, γ = 72°