If two vectors \(\overrightarrow a\) and \(\overrightarrow b \) be such that \(\left| {\overrightarrow a + \overrightarrow b } \right| = \left| {\overrightarrow a - \overrightarrow b } \right|\), then the angle between them is
1
\(\frac{\pi }{4}\)
2
\(\frac{\pi }{3}\)
3
\(\frac{\pi }{2}\)
4
None of these