Answer:
=20.0
Explanation:
We can first find the value of the angle at B using the sine formula.
a/sine A=b/Sin B
9/sin 15=12/sin B
Sin B=(12 sin 15)/9
Sin B=0.345
B=20.18°
Therefore angle C =180-(15+20.18)
=144.82°
a/Sin A=c/Sin C
9/Sin 15=c/Sin 144.82
c=(9 sin 144.82)/sin15
=20.0