The horizontal line segment at the top of the polygon on the grid below is how many units long?​

Answer:6 units long.Step-by-step explanation:Given:A polygon drawn on a graph.In order to determine the distance of the horizontal line at the top, we find the coordinates of the end points and then use distance formula to find the exact distance.Let us label the polygon as ABCD as shown below. AB is the length of the horizontal line.Coordinates of A are [tex](x_1,y_1)=(-3, 4)[/tex] as seen in the graph. Coordinates of B are [tex](x_2,y_2)=( 3, 4)[/tex] as seen in the graph.Now, distance formula  for two points [tex](x_1,y_1)\ and\ (x_2,y_2)[/tex] is:[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\\d_{AB}=\sqrt{(3-(-3))^2+(4-4)^2}\\d_{AB}=\sqrt{(3+3)^2+0}\\d_{AB}=\sqrt{36}=6\ units[/tex]Therefore, the horizontal line at the top is 6 units long.