Unit 8 - Quadrilaterals

Sides that do not share an endpoint

Opposite sides

Sides that share an endpoint

Adjacent sides

Angles that share a side

Consecutive angles

Angles that do not share a side

Opposite angles

A segment that joins two opposite vertices

Diagonal

Parallelogram

A quadrilateral with both pairs of opposite sides parallel.

Rectangle

Equiangular quadrilateral

Rhombus

Equilateral quadrilateral

Square

Equiangular and equilateral quadrilateral

Kite

A quadrilateral with two pairs of congruent adjacent sides and no opposite sides congruent

Trapezoid

A quadrilateral with exactly one pair of parallel sides

Isosceles Trapezoid

A quadrilateral with exactly one pair of parallel sides and the other sides are congruent.

Properties of _ quadrilateral:

• Opposite sides parallel & congruent

• Opposite angles congruent

• Consecutive angles supplementary

• Diagonals bisect each other

Parallelogram

Properties of _ quadrilateral:

• Diagonals are perpendicular

• Diagonals bisect angles

• Properties of parallelograms

Rhombus

Properties of _ quadrilateral:

• Diagonals are congruent

• Properties of parallelograms

Rectangle

Properties of _ quadrilateral:

• Four 45-45-90 triangles formed by diagonals

• All properties of parallelogram, rhombus, and rectangle

Square

Properties of _ quadrilateral:

• One pair of opposite angles congruent

• Diagonals perpendicular to

• One diagonal bisected (shorter)

• One diagonal bisects one pair of angles (non congruent angles)

Kite

Properties of _ quadrilateral:

• one pair of parallel sides

• Median segment is parallel to bases and ½ of their sum

Trapezoid

Properties of _ quadrilateral:

• base angles congruent

• Opposite angles supplementary

• Diagonals congruent

• One pair of parallel sides, other pair is congruent

Isosceles Trapezoid

Varigon’s Theorem

The midpoints of the sides of a quadrilateral join to form a parallelogram.