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