The stress tensor at a point on a plane is given as \(\left[ {\begin{array}{*{20}{c}} {110}&{25}\\ {25}&{60} \end{array}} \right]\) N/mm2. The sum of the normal stresses at a plane making an angle of 45° from the given plane will be
1
88 N/mm2
2
110 N/mm2
3
60 N/mm2
4
170 N/mm2