Question 1166407
<pre>
The perimeter, 4*27" = 108" consists of n tacks and n-1 gaps between them, so

{{{n(7/16)+(n-1)(1/4)=108}}}

Solve that for n, get

{{{1732/11=157&5/11}}}

so there's 157 tacks and the extra 5/11" of space is because the tacks are not
exactly tangent to the edge.

Edwin</pre>