Where is the plane now?

Hi guys, today I'll post a brain teaser for you.

There was a plane departing from an airport located in the North pole. The plane flew 40 miles to the south. Then, it changed its direction and flew 30 miles to the east and stopped there.

The question: How far was the plane from the North Pole?

Answer the question by giving comments to this post.

Good luck! In a few days, I'll give you the answer.