isi-entrance 2010 Q21

isi-entrance · India · solved Sine and Cosine Rules Multi-step composite figure problem

Let $A_1, A_2, \ldots, A_n$ be the vertices of a regular polygon and $A_1A_2$, $A_2A_3$, $\ldots$, $A_{n-1}A_n$, $A_nA_1$ be its $n$ sides. If $\left(\frac{1}{A_1A_2}\right) - \left(\frac{1}{A_1A_4}\right) = \frac{1}{A_1A_3}$, then the value of $n$ is
(a) 5
(b) 6
(c) 7
(d) 8

Let $A_1, A_2, \ldots, A_n$ be the vertices of a regular polygon and $A_1A_2$, $A_2A_3$, $\ldots$, $A_{n-1}A_n$, $A_nA_1$ be its $n$ sides. If $\left(\frac{1}{A_1A_2}\right) - \left(\frac{1}{A_1A_4}\right) = \frac{1}{A_1A_3}$, then the value of $n$ is\\
(a) 5\\
(b) 6\\
(c) 7\\
(d) 8

Paper Questions

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