(1)由题意知,周长为12.56厘米的圆的半径为:
12.56÷π÷2,
=12.56÷3.14÷2,
=2(厘米);
半径为2厘米的圆如下图所示:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/a044ad345982b2b7a171f77532adcbef77099b91?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
正方形的面积为:4×(2×2÷2)=8(平方厘米);
答:这个正方形的面积是8平方厘米.
(2)据分析画图形的对称轴如下所示:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/faf2b2119313b07ea2629eb90fd7912396dd8ca0?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
(3)左边图形中阴影部分的面积为:
8×(8÷2)-3.14×(8÷2)
2÷2,
=32-3.14×16÷2,
=32-25.12,
=6.88(平方厘米);
右边图形中阴影部分的面积是:
8×6-3.14×(6÷2)
2,
=48-3.14×9,
=48-28.26,
=19.74(平方厘米);
答:阴影部分的面积分别为6.88平方厘米和19.74平方厘米.
故答案为:8.