✔ 最佳答案
Use the Sine Rule
Which is
SinA/a = SinB/b = SinC/c
Permutate any two of the above out of the three.
Hence
SinA/a = SinC / c =>
SinA = a*SinC/c
SinA = 10.9 (Sin50) / 30.2
SinA = 10.9(0.766044443) / 30.2
SinA = 0.276486239...
A = Sin^-1(0.2764...)
A = 16.05 degrees.
A = 16 degrees ( nearest degree).