Can You Solve the Two Points in a Square Puzzle?

This one is really hard — you need to know calculus and probability theory! 

Mind Your Decisions has a new math puzzle, and its difficulty level is indicated as “Very Hard.”

Can you find the average distance between two random points in a square with a side length of 1?  

The video goes through how to estimate the exact answer using integrals. Those of you without a mathematical background will find this puzzle challenging, as knowledge in calculus and probability theory are necessary to solve it.  

The solution is explained towards the end of the video. Good luck!