For this case we have that by definition, the distance between two points is given by:
[tex]d = \sqrt {(x_ {2} -x_ {1}) ^ 2+ (y_ {2} -y_ {1}) ^ 2}[/tex]
We have the following points:
[tex](x_ {1}, y_ {1}) = (- 6, -8)\\(x_ {2}, y_ {2}) = (6,8)[/tex]
Substituting:
[tex]d = \sqrt {(6 - (- 6)) ^ 2+ (8 - (- 8)) ^ 2}\\d =\sqrt {(6 + 6) ^ 2 + (8 + 8) ^ 2}\\d = \sqrt {(12) ^ 2 + (16) ^ 2}\\d = \sqrt {144 + 256}\\d = \sqrt {400}\\d = 20[/tex]
ANswer:
20
