Question
Target: an 'L-shaped' tetromino made of four small squares — three squares in a vertical column with one square attached to the bottom-right.
Options:
- A: the same L-shape rotated 90° clockwise
- B: the same L-shape reflected horizontally (mirror image, forming a 'J')
- C: the same L-shape rotated 180°
- D: a T-shaped tetromino
- E: a square (2×2) tetromino
Identify which options are considered to belong to the same 'shape family' as the target under the GL convention that rotations count as the same shape but reflections do not.
Mark scheme (5 marks):
- Correct answers: A and C (2 marks — 1 each)
- Correct rejection of B because it is a reflection (chirality changes), not a rotation (1 mark)
- Correct rejection of D (T-tetromino — different connectivity of squares) (1 mark)
- Correct rejection of E (square tetromino — different number of arrangement) (1 mark)
5 marks · take your time before peeking.
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Generated by TopMyGrade AI · cross-check official sources before relying on the mark-scheme phrasing.