## Precalculus (10th Edition)

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