For Exercises 39–40, refer to the following. Step patterns are found in Celtic illuminated manuscripts, metalwork, and stone crosses. Square ones were constructed by first designing on a square lattice one- quarter of the pattern (say, the top right), using horizontal and diagonal lines to produce a prototype such as the following:

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Then three copies were added, either by (1) rotating the original successively by 90° [as in accompanying illustration (a)], or else by (2) reflecting it across its right and bottom edges [as in illustration (b)]. (Based on research by Mark A. M. Lynch of Glasgow Caledonian University, Scotland.)

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Question 19.69

39. Identify the rosette pattern for

  1. step pattern (a).
  2. step pattern (b).

39.

(a)

(b)