A + B = 120 o $\tan {{A - B} \over 2} = {{a - b} \over {a + b}}\cot \left( {{c \over 2}} \right)$ $= {{\sqrt 3 + 1 - \sqrt 3 + 1} \over {2\left( {\sqrt 3 } \right)}}\cot \left( {{{30}^o}} \right) = {1 \over {\sqrt 3 }}.\sqrt 3 = 1$ ${{A - B} \over 2} = {45^o}$ $\Rightarrow A - B = {90^o}$ $\ A + B = {120^o}$ $2A = {210^o}$ $A = {105^o}$ $B = {15^o}$ $\therefore$ $\angle A:\angle B,$ = 7 : 1