Study the graph and answer each of the following :

(a) Write the coordinates of points A, B, C and D.

(b) Given that, point C is the image of point A. Name and write the equation of the line of reflection.

(c) Write the coordinates of the image of the point D under reflection in y-axis.

(d) What is the name given to a point whose image is the point itself ?

(e) On joining the points A, B, C, D and A in order, a figure is formed. Name the closed figure.

(a) From graph,

Coordinates of A = (3, 3), B = (-2, 1), C = (3, -1) and D = (0, 1).

(b) From graph,

C is the image of point A in the line y = 1.

Hence, the line is BD and its equation is y = 1.

(c) Since, point D lies on y-axis, thus it is invariant under reflection in y-axis.

Hence, coordinates of point D on reflection in y-axis is (0, 1).

(d) A point whose image is the point itself is called invariant point.

(e) On joining the points A, B, C, D and A in order the figure formed is a concave quadrilateral or arrowhead.