Lesson 141 of 171

Area of a Circle
Students learn that the formula for the area of a circle is pi times radius squared, so the area of a circle that has a radius of 5 inches is pi times 5 squared, or 25 pi square inches. And since pi = 3.14, 25 pi square inches can also be written as 25 times 3.14, or 78.5 square inches.  more...
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