Why do this problem?
This challenging activity offers a context in which learners can apply knowledge of transformations. Although best done practically for many pupils, some may draw on visualisation skills, at least to make hypotheses before confirming practically. The triangular arrangement of dots helps to familiarise pupils with different angles.
This activity, as well as being done in ones or twos by the pupils, could be introduced by you challenging all the class at once. The first picture could be presented on screen, and you could ask the pupils what they would have to do with it to to see the next two pictures. You could provide pairs or small groups of pupils with an acetate grid and some dry-wipe pens to create each image for
You may wish to download and print these sheets for pupils:
(The first contains just the square grids, the second contains the triangular grids.)
Which peg/s might be helpful to focus on to begin with?
Have you tried flipping/rotating the original grid?
As suggested in the question itself, learners could be challenged to tweak the task slightly and pose their own problems. For example, they could use more/fewer blue pegs; use a different grid etc.
Plenty of dotty paper will be helpful and/or dotty grids on acetate sheets so that pupils can compare two patterns easily.