填空题If a circle has an area of 49π, what is the diameter of the circle?____
填空题
If a circle has an area of 49π, what is the diameter of the circle?____
参考解析
解析：
因为圆的面积为πr2，πr2 =49π，r=7，直径为2r=14。
因为圆的面积为πr2，πr2 =49π，r=7，直径为2r=14。
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