How do you convert -70 degrees into radian measure?

$- 90 \mathrm{de} g i s \equiv a \le n t \to : - \frac{\pi}{2}$
$- 70 \mathrm{de} g i s \equiv a \le n t \to : x r a \mathrm{di} a n$
$x = \left(- \frac{\Pi}{2}\right) . \left(\frac{7}{9}\right) = - \frac{7 \pi}{18}$