Answer:
the length of third side is 16.
Step-by-step explanation:
We can use Law of Cosine to find the third side of the triangle.
Law of Cosine is given by
\(a^2=b^2+c^2-2bc\cosA\)
Substituting the known values, we get
\(a^2=12^2+19^2-2\cdot12\cdot19\cos56\)
On simplifying, we get
\(a^2=505-456\cos56\\\\a^2=250.008\\\\a=15.81\)
When rounded to nearest whole number, the length of third side is 16.
