CK-12 Geometry-Concepts

6.5. Parallelogram Classification http://www.ck12.org

Guided Practice

1. Is a rectangle SOMETIMES, ALWAYS, or NEVER a parallelogram? Explain why.


2. Is a rhombus SOMETIMES, ALWAYS, or NEVER equiangular? Explain why.


3. Is a quadrilateral SOMETIMES, ALWAYS, or NEVER a pentagon? Explain why.

Answers:

1. A rectangle has two sets of parallel sides, so it is ALWAYS a parallelogram.


2. Any quadrilateral, including a rhombus, is only equiangular if all its angles are 90◦. This means a rhombus is
   SOMETIMES equiangular, only when it is a square.


3. A quadrilateral has four sides, so it will NEVER be a pentagon with five sides.

Interactive Practice

MEDIA

Click image to the left for use the URL below.

URL: http://www.ck12.org/flx/render/embeddedobject/113036

Explore More

1.RACEis a rectangle. Find:

a.RG

b.AE

c.AC

d.EC

e.m^6 RAC

2.DIAMis a rhombus. Find: