Question 913296
The perimeter is 
{{{ P = 2*30 + 2*60 }}}
{{{ P = 60 + 120 }}}
{{{ P = 180 }}}
There are 180 1' by 1' tiles plus
{{{ 4 }}} more for the corners, so
there are:
{{{ 180 + 4 = 184 }}} tiles