$\frac{c + a}{b}$ এর মান কোনটি ?

$\begin{array}{l}\angle C=180^{\circ}-\left(120^{\circ}+30^{\circ}\right)=30^{\circ} \\ \therefore \frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}=2 R \\ \therefore \frac{a}{\sin 30^{\circ}}=\frac{b}{\sin 120^{\circ}}=\frac{c}{\sin 30^{\circ}}=2 R \\ \therefore \frac{a}{\frac{1}{2}}=2 \times 1|\quad| \frac{c}{\frac{1}{2}}=2 \times 1 \mid \frac{b}{\frac{\sqrt{3}}{2}}=2 \\ \therefore a=1 \\ \therefore \frac{c}{\therefore}=1 \\ \therefore \frac{c+a}{b}=\frac{1+1}{\sqrt{3}}=\frac{2}{\sqrt{3}} \end{array}$