171- According to the figure below, ray SI after reflecting from flat mirrors is reflected along path $I'R$. The angle $\beta$ is how many times the angle $\alpha$? \begin{minipage}{0.4\textwidth} [Figure: Two flat mirrors meeting at an angle, with incident ray I making angle $\alpha$ with the lower mirror, ray reflecting off both mirrors, angle $\beta$ shown between rays at upper mirror, and final reflected ray $I'R$] \end{minipage} \begin{minipage}{0.55\textwidth} (1) $1$ (2) $2$ (3) $\dfrac{3}{2}$ (4) It depends on the angle of incidence of mirror (1). \end{minipage}
\textbf{171-} According to the figure below, ray SI after reflecting from flat mirrors is reflected along path $I'R$. The angle $\beta$ is how many times the angle $\alpha$?
\begin{minipage}{0.4\textwidth}
\textit{[Figure: Two flat mirrors meeting at an angle, with incident ray I making angle $\alpha$ with the lower mirror, ray reflecting off both mirrors, angle $\beta$ shown between rays at upper mirror, and final reflected ray $I'R$]}
\end{minipage}
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\begin{minipage}{0.55\textwidth}
(1) $1$
(2) $2$
(3) $\dfrac{3}{2}$
(4) It depends on the angle of incidence of mirror (1).
\end{minipage}