Question

find the distance between point A (2,1) and point B (7,13)

Answer 1

$d=\sqrt[]{(x2-x1)^2+(y2-y1)^2}$

then solve

$\begin{gathered} d=\sqrt[]{(7-2)^2+(13-1)^2} \\ d=\sqrt[]{5^2+12^2} \\ d=\sqrt[]{25+144} \\ d=\sqrt[]{169} \\ d=13 \end{gathered}$

answer: distance = 13