How to Find the Area of a Rectangle

Teacher explaining to young student.
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A rectangle is one of the most common geometric shapes. It is a four-sided figure with four right angles and opposite sides have the same measure. Finding the area of a rectangle is a relatively simple task and is often required in real life situations. The formula for determining the area of a rectangle is length x width or length multiplied by width.

    Measure the length of the rectangle. The length is the longest side of the rectangle. Write down the measurement so that you will have it when you are ready to use the formula. For example, the long side of a flower bed in the shape of a rectangle could measure 8 feet.

    Measure the width of the rectangle. This will be the shortest side and is always shorter than the length. Write down the measurement. For example, and using the same flower bed example, the width could measure 4 feet.

    Multiply the length measurement times the width measurement. These are the two measurements that you found in steps two and three. So, if you multiply 8 feet times 4 feet, you get 32 square feet as the area of the rectangular-shaped flower bed.

    Things You'll Need

    • Ruler or tape for measuring
    • Pencil or pen
    • Paper
    • Calculator, optional

    Tips

    • Remember that area is always expressed in square units. For example, if the measurements of length and width are in inches the area will be in square inches. If the measurements are in meters, the area will be expressed in square meters. Mathematics students are often asked to find the area of a rectangle when given the measures of the length and width. In this case, the measuring in steps two and three won't be necessary. Simply use the measurements given in the problem and apply the area formula.

    Warnings

    • The formula for area of a rectangle is only valid if the length and width measurements are in the same units. For example, if the length is measured in feet and the width in meters the product obtained when multiplying them together does not represent the correct area of the rectangle.

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