Quadrilateral Shapes- A four sided polygon

Quadrilateral Shapes- A four sided polygon

Common Core Standard . 7.G.6

What is a quadrilateral?

  • The key to a quadrilateral is found in it’s name, “Quad” meaning four and “lateral” meaning side. 
  • A quadrilateral is a four sided polygon. In addition a quadrilateral can be convex or concave. 
  • concave quadrilateral has one reflex angle, or an angle greater than 180 degrees. The reflex angle creates a cavity or a cave, which becomes an easy method to remember a concave quadrilateral. 
  • An example of a concave quadrilateral is a dart. 
  • A “complex quadrilateral” or “self-intersecting” quadrilateral have non-adjacent sides that cross over.

Names of Polygon Shapes

This Venn diagram helps to visualize the relationships among the different Quadrilaterals. 
 
Quadrilaterals can be separated into the following sub-groups.
 
  • General quadrilaterals 
  • Trapezoids 
  • Parallelograms
 
Squares have all the properties of a quadrilateral, a rhombus, a parallelogram, and a rectangle.
 
trapezoid is a quadrilateral based on its four sides, but has only one pair of parallel sides which eliminates it from being a parallelogram.
 
kite is a quadrilateral, but not a parallelogram because the opposite sides are not parallel or congruent.