Math - 2018-19

4.12 - Quadrilaterals

The student will 

  • classify quadrilaterals as parallelograms, rectangles, squares, rhombi, and/or trapezoids. 

Adopted: 2016


  • So that I can identify the relationship that polygons have in my everyday life

  • So that I can use polygons to complete tangrams and puzzles

  • So that I can see how polygons are used in architectural design, building blueprints, and so much more

  • So that I can describe shapes, using their proper name, after recognizing its characteristics


  • A quadrilateral is a polygon with four sides.
  • A parallelogram is a quadrilateral with both pairs of opposite sides parallel and congruent.
  • Congruent figures have the same size and shape.  Congruent sides are the same length.
  • A rectangle is a quadrilateral with four right angles, and, opposite sides that are parallel and congruent.

  • The geometric markings shown on the rectangle below indicate parallel sides with an equal number of arrows and congruent sides indicated with an equal number of hatch (hash) marks.
  •   A square is a rectangle with four congruent sides and four right angles. 
  •   A trapezoid is a quadrilateral with exactly one pair of parallel sides.

  • A rhombus is a quadrilateral with 4 congruent sides. Properties of a rhombus include the following:

      • opposite sides are congruent
      • opposite sides are parallel
      • opposite angles are congruent


The student will use problem solving, mathematical communication, mathematical reasoning, connections and representation to

  • Develop definitions for parallelograms, rectangles, squares, rhombi, and trapezoids.
  • Identify properties of quadrilaterals including parallel, perpendicular, and congruent sides.
  • Classify quadrilaterals as parallelograms, rectangles, squares, rhombi, and/or trapezoids.
  • Compare and contrast the properties of quadrilaterals.
  • Identify parallel sides, congruent sides, and right angles using geometric markings to denote properties of quadrilaterals.


Updated: Aug 22, 2018