text: The pythagorean theorem is c^2 = a^2 + b^2\n\nWhich means if you drew a straight line between the two points, you would have "c", which is the long side of a right triangle.  "a" and "b" form the sides.\n\nSo in your first example, -2 and 3 represent the "width", or horizontal edge, of your triangle.  Subtract the smaller value from the larger to get the length:\n\na = 3 - (-2)\na = 5\n\n-1 and 11 represent the "height", or vertical edge:\n\nb = 11 - (-1)\nb = 12\n\nSo your equation is this:\nc ^ 2 = a ^ 2 + b ^ 2\nc ^ 2 = 5 ^ 2 + 12 ^ 2\nc ^ 2 = 25    + 144\nc ^ 2 = 169\nc = 13\n\nSo the distance between E and F is 13.