\magnification=\magstep1

$$
A_{\rm tot} \quad = \quad A \thinspace 
           \biggl[ {{\sin(N \phi/2)}\over{\sin(\phi/2)}} \biggr]
$$

$$
L \quad = \quad R \thinspace \sin \left( {{\alpha}\over{2}} \right)
$$

$$
A_{\rm tot} \quad = \quad 2 L \quad = \quad 
                      2 R \thinspace \sin \left( {{\alpha}\over{2}} \right)
$$

$$
M \quad = \quad R \thinspace \sin \left( {{\phi}\over{2}} \right)
$$

$$
A \quad = \quad 2 M \quad = \quad 
                      2 R \thinspace \sin \left( {{\phi}\over{2}} \right)
$$

$$
{{A_{\rm tot}}\over{A}} \quad = \quad
    {  {    2 R \thinspace \sin \left( {{\alpha}\over{2}} \right) } 
       \over
       {    2 R \thinspace \sin \left( {{\phi}\over{2}} \right)   }  }
$$

$$
\alpha \quad = \quad N \thinspace \phi
$$

$$
{{A_{\rm tot}}\over{A}} \quad = \quad
    {  {    2 R \thinspace \sin \left( {{N \phi}\over{2}} \right) } 
       \over
       {    2 R \thinspace \sin \left( {{\phi}\over{2}} \right)   }  }
$$

$$
A_{\rm tot} \quad = \quad A \thinspace \thinspace 
   \Biggl[ 
    {  {    \thinspace \sin \left( {{N \phi}\over{2}} \right) } 
       \over
       {    \thinspace \sin \left( {{\phi}\over{2}} \right)   }  }
   \Biggr]
$$




\bye
