On which triangle can the law of cosines be used to find the length of an unknown side? law of cosines: a2 = b2 + c2 – 2bccos(a)

A²=b²+c²-2bc Cos (a)
In this case , we can find the length of side a using the above cosine law.
If you are given the values of side b , c and angle a, then it is easy to calculate the length of side a.
To find side b,
b²=a²+c²-2ac Cos(b)
To find side c,
c²=b²+c²-2bc Cos (c)
Just the given values in the formula and get the length of the missing side. You can also find the missing angle using these formulas.

I hope this will help you.