## 18 terms · If I don't say a property is reversible (meaning you could prove something is that quadrilateral based on that property) that doesn't mean it necessarily isn't reversible, I just haven't learned that it is yet. Also lists of properties don't include properties that are a part of the definition of a quadrilateral.

### Parallelogram Definition

A quadrilateral in which both pairs of opposite sides are parallel

### Parallelogram Properties

All are reversible: its opposite sides are congruent, its diagonals bisect each other, its consecutive angles are supplementary, its opposite angles are congruent

### Rectangle Definition

A parallelogram with at least one right angle

### Rectangle Properties

All the properties of a parallelogram, all of its angles are right angles, its diagonals are congruent

### Kite Definition

A quadrilateral in which two distinct pairs of sides are congruent

### Kite Properties

Its diagonals are perpendicular, one diagonal is the perpendicular bisector of the other, one pair of opposite angles are congruent, one diagonal bisects a pair of opposite angles

### Square Definition

A parallelogram that is both a rectangle and a rhombus

### Square Properties

All properties of parallelograms, rectangles, and rhombuses, its diagonals form four right isosceles triangles

### Rhombus Definition

A parallelogram with at least two consecutive congruent sides

### Rhombus Properties

All properties of parallelograms, its diagonals are each others perpendicular bisectors, both pairs of opposite angles are congruent, its diagonals bisect the pairs of opposite angles (reversible), it is equilateral, its diagonals divide it into four congruent right triangles (reversible)

### Trapezoid Definition

A quadrilateral with exactly one pair of parallel sides. (these are the bases)

### Isosceles Trapezoid Definition

A trapezoid in which the non-parallel sides (the legs) are congruent

### Isosceles Trapezoid Properties

both separate pairs of base angles are congruent, its diagonals are congruent, its lower and upper base angles are supplementary

### Proving Rectangles

If a parallelogram has at least on right angle or congruent diagonals, if a quadrilateral has 4 right angles

### Proving Kites

If two disjoint pairs of sides are congruent, if one of its diagonals perpendicular bis. the other, if one diagonal bisects a pair of opposite angles

### Proving Rhombuses

If its diagonals perpendicular bis. each other, if its diagonals divide it into 4 congruent right triangles, if a parallelogram has a pair of consecutive sides that are congruent, if either diagonal of a parallelogram bisects two of its angles

### Proving Squares

If it is both a rectangle and a rhombus, if its diagonals divide it into 4 right isosceles triangles

### Proving that Trapezoids are Isosceles

It its nonparallel sides are congruent, if its lower or upper base angles are congruent, if its diagonals are congruent.