 The sine law is used to solve non-90° triangles. 
Angles A, B and C are in degrees, and are across from sides a, b and c You can use any pair of sides and angles, to find a missing side or angle. Finding a Missing Side Example 1: Find side X 
x 12 -------- = -------- sin35 sin70 x·sin70 = 12·sin35 x = 12·sin35 / sin70 = 7.3 rounded to 1 d.p. Example 2: Find side X 
x 16--------- = -------- sin120 sin40 Notice that we must use 16 and angle 40° x·sin40 = 16·sin120 x = 16·sin120 / sin40 = 21.6 rounded to 1 d.p. Next let's look at how to find a missing angle >>> |