Block printing

In your book, Maths Mela (Chapter 10), we learn about block printing, a traditional craft of Rajasthan. Artisans carve a design into a wooden block, dip it in colour and press it onto cloth to print the design.

The book shows a wooden block shaped like a long leaf. The artisan prints it 4 times around the same centre point, turning the block 1/4 of a turn before each new print. The four leaves point up, right, down and left from the centre. This is design A. Because each leaf was made by turning the block 1/4 of a turn, the whole design looks the same after every 1/4 turn: after 1/4, 1/2, 3/4 and a full turn.

Design B in the book has four hearts that meet at the centre, one pointing up, one right, one down and one left. It too looks the same after every 1/4 turn, so it has rotational symmetry.

The number of prints and the size of the turn go together. If the leaf block is printed only 2 times, turning it 1/2 a turn for the second print, the two leaves point up and down from the centre. That design looks the same after 1/2 a turn, but not after 1/4 of a turn, because then the leaves would point left and right.