Geometrica Fights Back

Mystery of the Guilty Quadrilateral

Once upon a time long, long ago in a far, far away land known as Geometrica there occurred an unspeakable crime. On a dark and dreary night as the Circular family lay sleeping in their soft, round beds and dreaming of their favorite dessert, pi, a violent criminal murdered them. Their neighbor, Mrs. Equi Angular said that she and her husband, Mr. Tri Angular, heard the awful blood curdling screams. So, they sprang from their bed to see what was the matter, and what to their wandering eyes did appear (not eight tiny reindeer) but a strange four-sided figure leaping from the Circular’s upstairs window. Well, the Angulars gave a description of the terrible beast and so did many other Geometrica residents. However, to this day, the mystery remains. Therefore, Detective Pentagonal Walsh of Geometrica’s Most Wanted has asked for your assistance in solving this crime. Below you will find descriptions that tipsters have given the authorities. Your job is to list the suspects from your line-up of twelve that meet each set of criteria.

1. Four-sided figure and convex

Suspects:______

2. Four-sided figure with two sets of parallel sides

Suspects:______

3. Four-sided figure with four right angles

Suspects:______

4. Four-sided figure with all sides equal

Suspects:______

5. Four-sided figure whose diagonals bisect each other

Suspects:______

6. Four-sided figure whose opposite angles are congruent

Suspects:______

7. Four-sided figure with only one set of parallel sides

Suspects:______

8. Four-sided figure whose consecutive angles are supplementary

Suspects:______

9. Four-sided figure whose diagonals are congruent

Suspects:______

10. Four-sided figure whose diagonals are perpendicularSuspects:______

11. Four-sided figure with all equal sides and four right angles

Suspects:______

12. Four-sided figure with all equal sides and perpendicular diagonals

Suspects:______

13. Four-sided figure with all equal sides and congruent diagonals

Suspects:______

14. Four-sided figure whose legs are congruent

Suspects:______

15. Four-sided figure whose opposite sides are congruent

Suspects:______

16. Four-sided figure and concave

Suspects:______

17. Four-sided figure with exactly one pair of opposite angels that are congruentSuspects:______

18. Four-sided figure with no parallel sides

Suspects:______

19. Four-sided figure with two right angles

Suspects:______

20. Four-sided figure with no equal sides (scalene)

Suspects:______

21. Suspect might be a parallelogram.

Suspects:______

22. Suspect might be a trapezoid.

Suspects:______

Who killed the Circulars? The guilty quad is the one whose number appears the most in the above list.

Suspect number ______is the criminal.