Answer
$21.8^{\circ}$
Work Step by Step
To convert $21^{\circ} 48'$ to decimal degrees, let's break it as-
$21^{\circ} 48'$ = $21^{\circ}$ + $48'$
Now on dividing $48'$ by 60, we have the number of "decimal degrees" equivalent
to $48'$ (as $ 1^{\circ} = 60'$)
Therefore
$21^{\circ} 48'$ = $21^{\circ}$ + $(\frac{48}{60})^{\circ}$
$21^{\circ} 48'$ = $21^{\circ}$ + $0.8^{\circ}$
$21^{\circ} 48'$= $21.8^{\circ}$
