Properties

A parallelogram is the first kind of quadrilateral covered in this unit. A parallelogram is a quadrilateral with opposite sides parallel, as shown below.

ParDef

From the fact that opposite sides are parallel, many other properties become apparent:  

  • The opposite angles of a parallelogram are congruent.

Par1

  • The opposite sides of a parallelogram are congruent.

    Par2

  • The consecutive angles of a parallelogram are supplementary.

Par3b

  • The diagonals of a parallelogram bisect each other.

    Par4

All of the properties that apply to a parallelogram, can be used to find unknown quantities.  Be careful when determining which one to use.

 

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