



 
Hi Edwin, I need to know how tall you want the lamp. I need either the height $h$ or the slant height $s.$ Penny We received the reply : h six &one half” S 9” In my digram $ABC$ is a right triangle so Pythagoras Theorem gives \[S^2 = r^2 + h^2\] and thus if $r = 8$ inches and $h = 6$ inches than \[S^2 = 8^2 + 6.5^2 = 106.25\] and thus $S = 10.3$ inches so I am not sure what value to use for $S.$ Regardless, if you look at Stephen's response to a similar question you will find the expression \[\frac{\mbox{lateral area}}{\pi \; S^2} = \frac{2 \pi \; r}{2 \pi \; S}\] which simplifies to \[\mbox{lateral area} = \pi \; r \times S.\] I hope this helps,  


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