Question 442677
Let s be one side of the hexagon. Since this is a regular hexagon, each side will be called s.

then {{{6s = 84}}}  We know that s = (x+4).  Then, {{{6(x+4) = 6x + 24 = 84 }}}
{{{6x = 60}}}

So, {{{x = 10}}}

Plug this back into s = x+4, then {{{ s = 10 +4 = highlight(14)}}}

Each side is 14mm.