I couldn't upload an image so I tried to get it linked!
https://free-picload.com/image/qJ0Mu3
a = √25 = 5
b = √32 = 5.656854249
c = AB = ?
∠C = 81.86989765º
The law of cosines: c² = a² + b² - 2ab * cos(C)
c² = 25 + 32 - 56.56854249 * 0.141421356
c² = 57 - 8
c = 7 
