\( \Large sin \ \alpha =\frac{\sqrt{3}}{2} \)
\( \Large \alpha =60 ^{\circ} \)
\( \Large cos \ \beta =\frac{\sqrt{3}}{2} \)
\( \Large \beta =30 ^{\circ} \)
\( \Large tan \gamma=1 \)
\( \gamma=45 ^{\circ} \)
so, \( \Large \alpha + \beta + \gamma=60 ^{\circ} +30 ^{\circ} +45 ^{\circ} =135 ^{\circ} \)