Quadrilaterals

Definition

• A quadrilateral is a closed geometric figure with four sides, four vertices, and four angles.

• The segments of a quadrilateral intersect only at their endpoints.

Quadrilaterals Not Quadrilaterals

3 sidesMore than

4 sidesMust only contain

Segments

Non consecutive sides should not

intersect

Naming Quadrilaterals

• Quadrilaterals are named by listing their vertices in order. There are many names for the quadrilateral below. Some examples are quadrilateral ABCD, quadrilateral BCDA, or quadrilateral DCBA.

Sides

• Any two sides, vertices, or angles of a quadrilateral are either consecutive or nonconsecutive.

• In a quadrilateral, nonconsecutive sides, vertices, or angles are also called opposite sides, vertices, or angles.

Diagonals

• Segments that join nonconsecutive vertices of a quadrilateral are called diagonals.

Properties

• The sum of all the angles equals 360º degrees.

90º

360º90º

90º

90º

90º 90º

90º 90º360º

65º 115º

65º115º

360º

90º 90º

90º 90º

360º110º 110º

70º70º

360º

Special Quadrilaterals• A quadrilateral is a four-sided

polygon, but some of them have characteristics that make them special.

• We will be covering 6 special quadrilaterals:– Parallelogram– Rectangle– Square– Rhombus– Kite– Isosceles Trapezoid

Six Special Quadrilaterals

Parallelogram Rectangle

Rhombus Square

IsoscelesTrapezoid

Kite

Special Quadrilateral Properties

• Each special quadrilateral has its on properties. However there are similarities between them.

• Your task is going to be to discover their properties by constructing and exploring each one.

Examples of Quadrilaterals in

Everyday Life

Parallelograms

Rectangles

Squares

Rhombi

Kites

Isosceles Trapezoids

Conclusion

• We will be covering 6 types of quadrilaterals– Parallelograms– Rectangles– Squares– Rhombi– Kites– Isosceles Trapezoids

As we explore the various quadrilaterals, begin thinking about all the places that you can find them, i.e. school, car, work, home, etc.