How do you evaluate sec 137?

$\sec {137}^{\circ} = - 1.3672$
$\sec {137}^{\circ} = \frac{1}{\cos} \left({137}^{\circ}\right) = \frac{1}{\cos} \left(180 - {137}^{\circ}\right)$
$\implies - \frac{1}{\cos} \left({43}^{\circ}\right) = - \left(\frac{1}{0.7314}\right) = - 1.3672$