Ok, so I’m working on a .blend with triangles, heres and example of what the triangle would look like.

What I’m doing is trying to get angle A.

a,b,c are known values so according to good old trigonometry:

```
a^2 = b^2 + c^2 - 2bc*cosA
```

So, I’m after A and after rearranging the formula I get this:

```
cosA = (a^2)/(b^2 + c^2 - 2bc)
```

This wouldn’t be problem on my calculator, but in python how do I find the exact value of A not the value of cosA, I looked at the math module but I couldn’t figure out what to use.

And also, did I rearrange it correctly?