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Parallelograms

In the parallelogram shown in Figure 1 , h is a height because it is perpendicular to a pair of opposite sides called bases. One of the bases has been labeled b, and the nonbase remaining sides are each labeled a.





Figure 1

A parallelogram with base and height labeled.


Finding the perimeter

The following formula is now apparent.





Finding the Area

In Figure 1 , also notice that Δ WXV ≅ Δ TYZ, which means that they also have equal areas. This makes the area of WXYT the same as the area of XYZV. But Arectangle XYZV = bh, so Aparallelogram XYTW = bh. That is, the area of a parallelogram is the product of any base with its respective height.





Example 1: Find the perimeter and area of Figure 2 .





Figure 2

Finding the perimeter and area of a parallelogram.


The figure is a parallelogram, so




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