http://www.ck12.org Chapter 6. Polygons and Quadrilaterals
6.3 Parallelograms
Here you’ll learn what a parallelogram is and how to apply theorems about its sides, angles, and diagonals.
What if a college wanted to build two walkways through a parallelogram-shaped courtyard between two buildings?
The walkways would be 50 feet and 68 feet long and would be built on the diagonals of the parallelogram with
a fountain where they intersect. Where would the fountain be? After completing this Concept, you’ll be able to
answer questions like this by applying your knowledge of parallelograms.
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MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/52566CK-12 Foundation: Chapter6ParallelogramsA
Learn more about parallelogram properties by watching the video at this link.
Guidance
Aparallelogramis a quadrilateral with two pairs of parallel sides. Here are some examples:
Notice that each pair of sides is marked parallel. As is the case with the rectangle and square, recall that two lines
are parallel when they are perpendicular to the same line. Once we know that a quadrilateral is a parallelogram, we
can discover some additional properties.