Use a graph paper for this question.
(Take 2 cm = 1 unit on both x and y axes) where A (0, 4), B (2, 3), C (1, 1) and D (2, 0) and reflect points B', C', D' on y-axis
Join the points A, B, C, D, D', C', B' and A in order, so as to form a closed figure. Write down the equation of the line about which if this closed figure obtained is folded, the two parts of the figure exactly coincide.

Answer

B'(-2, 3), C'(-1, 1), D'(-2, 0)