the distance formula:
[tex]d= \sqrt{ (x_{2} - x_{1}) ^{2}+ (y_{2} -y_{1}) ^{2} } [/tex]
A(1,1) B(7,-7)
[tex]d= \sqrt{ (7 - 1) ^{2}+ (-7 -1) ^{2} } [/tex]
[tex]d= \sqrt{ (6) ^{2}+ (-8) ^{2} } [/tex]
[tex]d= \sqrt{ 36 + 64 } [/tex]
[tex]d= \sqrt{ 100 } [/tex]
[tex]d=10[/tex]
The answer is 10
