15 divided by 3+13-8
2 answers:
You might be interested in
Law cosines: 
16 + 256 - 128
=> y ≈ 16.51;
Law sines: 16/sinx = 16.51/sin30 => sinx = 0.48 => x ≈ 29 degrees;
Law sines: 16/sinx = 16.51/sin30 => sinx = 0.48 => x ≈ 29 degrees;