练习十七
1.3.14×40=125.6(cm)
2. 126÷3.14÷2
=126÷(3.14×2)
=126÷6.28
≈20(厘米)
答:________________。
3. 1.57÷3.14÷2 3.14×0.25²≈0.20(平方米)
=0.5÷2 答:____________。
=0.25(米)
4.(1) 3.14×(10²-4²) (2)16÷2=8(dm)
=3.14×(100-16) 16×8÷2
=3.14×84 =128÷2
=263.76(cm²) =64(dm²)
3.14×8²÷2
=3.14×64÷2
=200.96(dm²)
64+200.96=264.96(dm²)
5.答:周长相等的情况下,圆形的面积最大,长方形的面积最小;面积相等的情况下,长方形的周长最长,圆的周长最短。
希望能解决您的问题。
追问![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d000baa1cd11728ba90d6c31cbfcc3cec3fd2c85?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/cefc1e178a82b90161b02320708da9773912ef80?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
本回答被网友采纳