If \(\left| {\overrightarrow a } \right| = 5\), \(\left| {\overrightarrow a - \overrightarrow b } \right| = 8\) and \(\left| {\overrightarrow a + \overrightarrow b } \right| = 10\), then the value of \(\left| {\overrightarrow b } \right|\) is:
1
1
2
√57
3
3
4
√42