Use the Law of Cosines.

$x^{2} = \left(7\right)^{2} + \left(10\right)^{2} − 2\left(7\right)\left(10\right)\operatorname{cos}\left(140°\right)$

$x =\sqrt{149-140 \text{cos(140º)}}$

$x ≈ 16.01'$

Use the Law of Sines.

$89.5°$