Answer
$\frac{2}{\sqrt 3}$
Work Step by Step
To find out exact value of $ \sec 30^{\circ}$, considering special triangle- $ 30^{\circ} - 60^{\circ} - 90^{\circ}$
$\sec 30^{\circ}$ = $\frac{hypotenuse}{side - adjacent - to - 30^{\circ}}$
$\sec 30^{\circ}$ = $ \frac{2}{\sqrt 3}$
