Let P denote the north pole then you can use the triangle CPE to calculate the distance CE. Use the Cosine rule of a spheric triangle: (d is the angle corresponding to the distance between C and E)
$\displaystyle \cos(d)=\sin(70^\circ) \sin(150^\circ) + \cos(70^\circ) \cos(150^\circ) \cos(70^\circ - 40^\circ)\approx 0.21333...$
which will yield $\displaystyle d \approx 77.68^\circ$