https://vle.mathswatch.co.uk/images/questions/question815.png
You can either use the Pythagorean Theorem or the distance formula (which is just the
Pythagorean Theorem adapted for coordinates:
d = sqrt( (x2 - x1)2 + (y2 - y1)2 ) = sqrt( (4 - -4)2 + (3 - -2)2 )
= sqrt( 82 + 52 = sqrt( 89 ) = ....
