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.