7 Braille is a system of writing for blind people. A rectangular pattern of 6 dots represents each letter of the alphabet. Some of the dots are large and some are small.
Here are the patterns for 6 letters.
(a) How many lines of symmetry has the pattern for D? (1)
(b) Write down the letter whose pattern has
(i) rotational symmetry of order 2 and 2 lines of symmetry,
(ii) rotational symmetry of order 2 but no lines of symmetry.
(2)
(c) On the grid below, use 2 large dots and 4 small dots to make a pattern which has rotational symmetry of order 2 but no lines of symmetry.(1)
