The radius of a circle is 4 decimeters, and its circumference is______ Decimeter, area is______ Square decimeter
The circumference of the circle is 2 × 3.14 × 4, = 6.28 × 4, = 25.12 (decimeter); the area of the circle is 3.14 × 42, = 3.14 × 16, = 50.24 (square decimeter); answer: the circumference of the circle is 25.12 decimeter; the area is 50.24 square decimeter
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