$(20$pts$)$ Design and instantiate a structure which has $2$ fields: color $($line color$),$ positions $($positions of a line$).$ color is represented by a string and positions is represented by a list which has only $2$ elements. Each element is a posn structure with $2$ fields: $x(x$ coordinate$)$ and y coordinate$).x$ and $y$ are represented by numbers. $($Do not forget to write down the functions constructors, selectors, and predicates. Solve Question $2,3$ by using that structure$)$

Distance of two points $A(x_1,y_1)$ and $B(x_2,y_2)$ is given by:

distance $(A,B)=\sqrt[\phantom{2}]{(x_1-x_2{)}^2+(y_1-y_2{)}^2}$