Originally Posted by^_^Engineer_Adam^_^

Where is the angle across from side c.

Thus .

The other formulae simply permute the values of a, b, and c and need not be given.

So for example, to find the angle across from side c we have:

Thus is second quadrant and

To find the angle across from side a, use a = 6, b = 9, c = 5. etc.

-Dan