Topic Category: Areas

Areas of Circles and Sectors

Now we move on to the world of coins and pizzas. A circle’s diameter is the distance of a straight line from one point on a circle to another point on the opposite edge while passing its center. The radius (plural: radii) is half the diameter and is the basis for calculating the area of a circle.  A sector of a circle …

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Areas of Regular Polygons

A regular polygon is any polygon that has all sides equal (equilateral) and all angles equal (equiangular). Some familiar examples we have seen so far are equilateral triangles and squares. As the number of sides increase to include pentagons (5-sided), hexagons (6-sided), and even decagons (10-sided), we often call them n-gons where n is the number of sides. Therefore, regular n-gons are …

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Areas of Trapezoids

Whereas a parallelogram has two pairs of parallel sides, a trapezoid is a quadrilateral with only one pair of parallel sides. The formula for the area of any trapezoid is where and are the lengths of each base of the parallel pair. We can all agree that this formula is a little more complex than …

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Areas of Rectangles and Squares

The area of any rectangle is the product of its base and height. Since squares are special rectangles with four equal sides, their areas are found as the product of two sides (See Figure 1). Once you have chosen one side as your base, keep in mind that the segment chosen as your height must be perpendicular (forms a right angle) …

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Introduction to Area

Students frequently encounter problems in calculating the area of shapes ranging from simple triangles to complicated shapes. Not many students realize, however, that they intuitively determine areas of various surfaces every day. You know right away that your iPad has a larger area than your laptop and fits in your backpack more easily. You don’t …

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