六上数学复习-圆&扇形

энтджей

2026-01-22 21:03:50

发布于：浙江

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六上数学复习整理

（防透视的不知名横线）

$\color{white}{请打开浅色模式}$ $\color{transparent}{什么？你竟然偷看！}$

正片：

1.圆：
- (1).认识圆：
  - 圆心 - O：用圆规画圆时，针尖所在的点叫做圆心
  - 直径 - d：通过圆心并且两端都在圆上的线段叫做直径
  - 半径 - r：连接圆心和圆上任意一点的线段叫做半径
  - r = $\frac{d}{2}$ = d / 2
  - d = 2r
- (2).周长：
  - 周长-C
  - C_圆 = πd = 2πr
- (3).面积
  - 面积-S
  - S_圆 = π(r)²
- (4).面积2
  - 设：
    - S_圆 = S_圆
    - S_{圆中方（圆中最大的正方形）}=S_小正
    - S_{圆外方（圆外最小的正方形）}=S_大正
  - S_圆 = π(r)² ; S_小正 = 2(r)² ; S_大正 = 4(r)²
  - S_大正：S_圆：S_小正 = 4(r)² ：π(r)² ：2(r)² = 4 ：π ：2 = 200 ：157 ：100
2.扇形：
- (1).认识扇形：
  - 圆上两点之间的部分叫作弧，如圆上AB两点之间的部分叫作“弧AB”
  - 一条弧和经过这条胡两端的两条半径所围成的图形叫做扇形
    -像∠AOB这样，点点在圆心的角叫做圆心角
- (2).周长：
  - C_扇形 = $\frac{∠AOB}{360°}$ · C_圆 = $\frac{∠AOB}{360°}$ · πd = $\frac{∠AOB}{360°}$ · 2πr = $\frac{∠AOB}{180°}$ · πr
- (3).面积
  - S_扇形 = $\frac{∠AOB}{360°}$ · S_圆 = $\frac{∠AOB}{360°}$ · π(r)²
3.解决问题：
- 暂无（懒的画图和解答）
4.确定起跑线：
- 跑一圈：道宽 * 2 * π
- 跑半圈（无特殊请况的话（一个直道一个弯道））：道宽 * π

附表：

备注：红色为必背内容

备注：灰色为特别好推算的（如：20π=2π * 10）

$\color{white}{这样看只会看到必背的和特别好推算的几个哟，打开浅色模式可以看完整附表}$

$\color{#121624}{这样看会看到完整附表哟，打开深色模式可以只看到必背备的和特别好推算的几个}$

$\color{red}{1π = 3.14}$
$\color{red}{2π = 6.28}$
$\color{red}{3π = 9.42}$
$\color{red}{4π = 12.56}$
$\color{red}{5π = 15.7}$
$\color{red}{6π = 18.84}$
$\color{red}{7π = 21.98}$
$\color{red}{8π = 25.12}$
$\color{red}{9π = 28.26}$
$\color{red}{10π = 31.4}$ && $\color{silver}{10π = 31.4}$
$\color{#121624}{11π = 34.54}$
$\color{red}{12π = 37.68}$
$\color{#121624}{13π = 40.82}$
$\color{#121624}{14π = 43.96}$
$\color{#121624}{15π = 47.1}$
$\color{red}{16π = 50.24}$
$\color{#121624}{17π = 53.38}$
$\color{red}{18π = 56.52}$
$\color{#121624}{19π = 59.66}$
$\color{gray}{20π = 62.8}$
$\color{#121624}{21π = 65.94}$
$\color{#121624}{22π = 69.08}$
$\color{#121624}{23π = 72.22}$
$\color{red}{24π = 75.36}$
$\color{red}{25π = 78.5}$
$\color{#121624}{26π = 81.64}$
$\color{#121624}{27π = 84.78}$
$\color{#121624}{28π = 87.92}$
$\color{#121624}{29π = 91.06}$
$\color{gray}{30π = 94.2}$
$\color{#121624}{31π = 97.34}$
$\color{red}{32π = 100.48}$
$\color{#121624}{33π = 103.62}$
$\color{#121624}{34π = 106.76}$
$\color{#121624}{35π = 109.9}$
$\color{red}{36π = 113.04}$
$\color{#121624}{37π = 116.18}$
$\color{#121624}{38π = 119.32}$
$\color{#121624}{39π = 122.46}$
$\color{gray}{40π = 125.6}$
$\color{#121624}{41π = 128.74}$
$\color{#121624}{42π = 131.88}$
$\color{#121624}{43π = 135.02}$
$\color{#121624}{44π = 138.16}$
$\color{#121624}{45π = 141.3}$
$\color{#121624}{46π = 144.44}$
$\color{#121624}{47π = 147.58}$
$\color{#121624}{48π = 150.72}$
$\color{#121624}{49π = 153.86}$
$\color{gray}{50π = 157}$
$\color{#121624}{51π = 160.14}$
$\color{#121624}{52π = 163.28}$
$\color{#121624}{53π = 166.42}$
$\color{#121624}{54π = 169.56}$
$\color{#121624}{55π = 172.7}$
$\color{#121624}{56π = 175.84}$
$\color{#121624}{57π = 178.98}$
$\color{#121624}{58π = 182.12}$
$\color{#121624}{59π = 185.26}$
$\color{gray}{60π = 188.4}$
$\color{#121624}{61π = 191.54}$
$\color{#121624}{62π = 194.68}$
$\color{#121624}{63π = 197.82}$
$\color{gray}{64π(32π*2） = 200.96}$
$\color{#121624}{65π = 204.1}$
$\color{#121624}{66π = 207.24}$
$\color{#121624}{67π = 210.38}$
$\color{#121624}{68π = 213.52}$
$\color{#121624}{69π = 216.66}$
$\color{gray}{70π = 219.8}$
$\color{#121624}{71π = 222.94}$
$\color{#121624}{72π = 226.08}$
$\color{#121624}{73π = 229.22}$
$\color{#121624}{74π = 232.36}$
$\color{#121624}{75π = 235.5}$
$\color{#121624}{76π = 238.64}$
$\color{#121624}{77π = 241.78}$
$\color{#121624}{78π = 244.92}$
$\color{#121624}{79π = 248.06}$
$\color{gray}{80π = 251.2}$
$\color{#121624}{81π = 254.34}$
$\color{#121624}{82π = 257.48}$
$\color{#121624}{83π = 260.62}$
$\color{#121624}{84π = 263.76}$
$\color{#121624}{85π = 266.9}$
$\color{#121624}{86π = 270.04}$
$\color{#121624}{87π = 273.18}$
$\color{#121624}{88π = 276.32}$
$\color{#121624}{89π = 279.46}$
$\color{gray}{90π = 282.6}$
$\color{#121624}{91π = 285.74}$
$\color{#121624}{92π = 288.88}$
$\color{#121624}{93π = 292.02}$
$\color{#121624}{94π = 295.16}$
$\color{#121624}{95π = 298.3}$
$\color{#121624}{96π = 301.44}$
$\color{#121624}{97π = 304.58}$
$\color{#121624}{98π = 307.72}$
$\color{#121624}{99π = 310.86}$
$\color{gray}{100π = 314}$