Determine the number of rectangles and hexagons in the given figure.
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Determine the number of rectangles and hexagons in the given figure.

- A.
30, 5
- B.
32, 3
- C.
28, 5
- D.
30, 3
Attempted by 2 students.
Show answer & explanation
Correct answer: A
In a compound figure built from several overlapping elementary regions, classify every candidate rectangle by how many elementary regions it is made of (1-region, 2-region, 3-region, and so on up to the largest combination), count each class separately, then add the classes together.
A hexagon in such a figure is any closed six-vertex boundary you can trace using the figure's labelled points; find every one by systematically tracing candidate six-sided boundaries around the diagram rather than guessing.
Label the figure as shown, with the outer points A-P and the inner points Q-W marking every intersection.

Rectangle class (components) | Rectangles (by label) | Count |
|---|---|---|
1 | CVSR, VETS, RSWM and STKW | 4 |
2 | CETR, VEKW, RTKM and CVWM | 4 |
3 | ACRP, PRMO, EGHT and THIK | 4 |
4 | CEKM, AVSP, PSWO, VGHS and SHIW | 5 |
5 | AETP, PTKO, CGHR and RHIM | 4 |
6 | ACMO and EGIK | 2 |
8 | AGHP, PHIO, AVWO and VGIW | 4 |
10 | AEKO and CGIM | 2 |
16 | AGIO | 1 |
Total rectangles = 4 + 4 + 4 + 5 + 4 + 2 + 4 + 2 + 1 = 30.
Tracing every six-vertex boundary the same way gives these hexagons:
CDEKLM
CEUKMQ
CFHJMQ
BEUKNP
BFHJNP
That gives 5 distinct hexagons.
Cross-checking against the other pairings shows why each is off:
32 rectangles over-counts by double-reading some of the larger multi-component rectangles (an eight- or ten-component rectangle counted from two overlapping directions), and 3 hexagons under-counts by missing two of the six-vertex boundaries that share edge points with the outer border.
28 rectangles under-counts by dropping an entire four-component class (shapes such as CEKM or VGHS, each built from two adjacent quadrant pieces).
3 hexagons under-counts for the same reason as above - two boundary hexagons sharing edge points with the outer border get missed when the trace isn't carried all the way around the figure.
So the figure contains 30 rectangles and 5 hexagons.