Practice with Quadrilaterals

Answers

1. Always true.
2. Sometimes true.
3. Always true.
4. Always true.
5. Always true.
6. Never true.
7. Must be a rectangle (and therefore a parallelogram), could be a square.
8. Must be a quadrilateral. Could be a kite, parallelogram, rectangle, rhombus, or square depending on which sides are congruent and additional properties.
9. Possible conjectures: diagonals are perpendicular, one diagonal bisects the other, one diagonal bisects its angles.
10. Possible conjectures: diagonals are congruent, diagonals bisect each other.
11. Possible conjectures: diagonals are perpendicular, diagonals bisect each other.
12. Possible conjecture: one pair of opposite angles are congruent.