[tex]\bf \textit{distance between 2 points}\\ \quad \\
\begin{array}{lllll}
&x_1&y_1&x_2&y_2\\
% (a,b)
Q&({{ -3}}\quad ,&{{ 5}})\quad
% (c,d)
R&({{ 2}}\quad ,&{{ 3}})
\end{array}\qquad
% distance value
d = \sqrt{({{ x_2}}-{{ x_1}})^2 + ({{ y_2}}-{{ y_1}})^2}
\\\\\\
QR=\sqrt{[2-(-3)]^2+[3-5]^2}\implies QR=\sqrt{(2+3)^2+(3-5)^2}
\\\\\\
QR=\sqrt{5^2+(-2)^2}\implies QR=\sqrt{25+4}\implies QR=\sqrt{29}[/tex]
