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.
- A 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.
A trapezoid is a quadrilateral based on its four sides, but has only one pair of parallel sides which eliminates it from being a parallelogram.
A kite is a quadrilateral, but not a parallelogram because the opposite sides are not parallel or congruent.
