How do you find the distance between (5,2), (8,-2)?

Hence, reqd. Distance $= 5$.
Denoting thr Dist. btwn, pts $A \left({x}_{1} , {y}_{1}\right) \mathmr{and} B \left({x}_{2} , {y}_{2}\right)$ is denoted by $A B$, is defined by
$A B = \sqrt{{\left({x}_{1} - {x}_{2}\right)}^{2} + {\left({y}_{1} - {y}_{2}\right)}^{2}}$.
Hence, reqd. Distance $= \sqrt{{\left(- 3\right)}^{2} + {4}^{2}} = 5$.