To get the distance between two points, we can use the formula given below
[tex]\text{distance betwe}en\text{ points = }\sqrt[]{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]From the question given, we were given the coordinates of points C and D to be
[tex]\begin{gathered} C\text{ = (-2, 13)} \\ D\text{ = (-18, -1)} \end{gathered}[/tex]we can put x1 = -2 and y1 = 13
and x2 = -18, y2 = -1
[tex]\sqrt[]{(-18_{}-(-2)_{})^2+(-1-13_{})^2}[/tex][tex]\begin{gathered} \sqrt[]{(-16)^2+(-14_{})^2} \\ \\ \Rightarrow\text{ }\sqrt[]{256\text{ + 196}} \\ \\ \Rightarrow\sqrt[]{452} \end{gathered}[/tex][tex]\sqrt[]{452}\text{ = 21.26}[/tex]The distance between points C and D = 21.26
=> 21.3 (To one decimal number)