Answer
$18^{\circ}15'18''$
Work Step by Step
We know that
$1^o = 60’$
$1’=60"$.
Use a calculator and the conversion factors above to obtain: $18.255^{\circ}\\=18^{\circ}+0.255\cdot60'\\=18^{\circ}+15.3'\\=18^{\circ}+15'+0.3\cdot60''\\=18^{\circ}+15'+18''$.