Divide a circle into 16 equal parts to form a short-sighted rectangle. The circumference of the rectangle is 41.4, and its area is
Half of the circumference of a circle is equal to the length of a rectangle, which is π R. the radius of a circle is equal to the width of a rectangle, which is r
The length of the rectangle is 2R longer than the circumference of the circle
2πR+2R=(2×3.14+2)×R=8.28R=41.4
R=41.4÷8.28
R=5
Its area is 3.14 × 5 & sup2; = 78.5
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