Answer
17$^{\circ}$01'49"
Work Step by Step
1. Redistribute a degree from the 90 and change it to 60 minutes. Then change one of minutes to 60 seconds.
$89^{\circ}59'60"- 72^{\circ}58'11" = ?$
2. Subtract separately then combine
$89^{\circ}-72^{\circ}=17^{\circ}$
$59'-58'=01'$
$60"-11"=49"$
$17^{\circ}01'49"$