Step 1: Recall the distance formula
\[
d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}
\]
Step 2: Substitute values
Points are $(x_1,y_1)=(2,3)$ and $(x_2,y_2)=(4,1)$.
\[
d = \sqrt{(4-2)^2 + (1-3)^2}
\]
\[
= \sqrt{(2)^2 + (-2)^2} = \sqrt{4 + 4} = \sqrt{8}
\]
Step 3: Simplify
\[
\sqrt{8} = 2\sqrt{2}
\]
\[
\boxed{d = 2\sqrt{2}}
\]
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.