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SectionB.2Parallelogram

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FigureB.2.1Parallelogram

The shape in Figure B.2.1 is called a parallelogram. It is a quadrilateral (\(4\)-sided polygon) with two pairs of parallel sides, and each side has the same dimension as its opposite side. Note that any rectangle is a special parallelogram with \(4\) right angles.

We can easily calculate a parallelogram's perimeter:

\begin{equation*} \text{parallelogram perimeter}=2(3\text{ cm}+1.7\text{ cm})=9.4\text{ cm} \end{equation*}

To calculate a parallelogram's area, let's look at this figure:

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FigureB.2.2Parallelogram's Area

Once we move the right triangle from the right side to the left side, a parallelogram can be turned into a rectangle with the same area. Thus, a paralleogram's area can be calculated by a rectangle's area formula:

\begin{equation*} \text{Parallelogram Area}=bh \end{equation*}

where \(b\) stands for the parallelogram's base and \(h\) for its height.

ExerciseB.2.3