方法如下:
1、用圆规画一个圆,设圆心为O;
/iknow-pic.cdn.bcebos.com/9f2f070828381f309e472e9fa4014c086e06f0ae"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/9f2f070828381f309e472e9fa4014c086e06f0ae?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/9f2f070828381f309e472e9fa4014c086e06f0ae"/>
2、画两条垂直的直径AB和CD;
/iknow-pic.cdn.bcebos.com/9a504fc2d562853501f771179def76c6a7ef63f5"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/9a504fc2d562853501f771179def76c6a7ef63f5?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/9a504fc2d562853501f771179def76c6a7ef63f5"/>
3、取AO的中点,作平行于CD的平行线FG并连接EC;
/iknow-pic.cdn.bcebos.com/6a63f6246b600c3321297dfe174c510fd9f9a1b0"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/6a63f6246b600c3321297dfe174c510fd9f9a1b0?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/6a63f6246b600c3321297dfe174c510fd9f9a1b0"/>
4、取EC的长度为半径,以D点为圆心作圆,设焦点为H,L;
/iknow-pic.cdn.bcebos.com/342ac65c10385343443024179e13b07eca80880d"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/342ac65c10385343443024179e13b07eca80880d?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/342ac65c10385343443024179e13b07eca80880d"/>
5、以EC的长度为半径,C点为圆心作圆,设焦点为J,K;
/iknow-pic.cdn.bcebos.com/3812b31bb051f819eec5a07cd7b44aed2e73e720"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/3812b31bb051f819eec5a07cd7b44aed2e73e720?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/3812b31bb051f819eec5a07cd7b44aed2e73e720"/>
6、连接点C,H,I,J,K,得到正五边形CHIJK;
/iknow-pic.cdn.bcebos.com/0bd162d9f2d3572c95113fea8713632762d0c311"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/0bd162d9f2d3572c95113fea8713632762d0c311?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/0bd162d9f2d3572c95113fea8713632762d0c311"/>
拓展资料:
正五边形
(1)五条长度相等的线段,首尾相连构成的一个封闭形状且内角相等的平面图形叫正五边形。正五边形每个角均为108°,每条边长度相等。正五边形是旋转对称图形,但不是中心对称图形。
(2)正五边形是指五个边等长且五个角等角的五边形,其内角为108度,是一种正多边形,在施莱夫利符号中可以用/iknow-pic.cdn.bcebos.com/503d269759ee3d6dc5a925fd4e166d224f4ade9d"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/503d269759ee3d6dc5a925fd4e166d224f4ade9d?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/503d269759ee3d6dc5a925fd4e166d224f4ade9d"/>来表示。正五边形的中心角为72度,其具有五个对称轴,其旋转对称性有5个阶(72°、144°、216°和288°)。
(3)正五边形不能镶嵌平面,因为其内角是108°,不能整除360°。截至2015年,已知有15种凸五边形镶嵌平面,还未知道是否尚有其他的凸五边形。
(4)约前300年,欧几里得在他的《几何原本》中描述了一个用直尺和圆规做出正五边形的过程。
(5)正五边形可以借由尝试在一张长条纸张上打一个反手结,并将多出来的部分向后折来构造。这种折法被用在折纸星星上。
/iknow-pic.cdn.bcebos.com/a8773912b31bb0519d1b1e1e3b7adab44aede0cd"target="_blank"title="点击查看大图"class="ikqb_img_alink">/iknow-pic.cdn.bcebos.com/a8773912b31bb0519d1b1e1e3b7adab44aede0cd?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto"esrc="
https://iknow-pic.cdn.bcebos.com/a8773912b31bb0519d1b1e1e3b7adab44aede0cd"/>
(资料来源:/baike.baidu.com/item/%E6%AD%A3%E4%BA%94%E8%BE%B9%E5%BD%A2/10808770?fr=aladdin#7_1"target="_blank">百度百科:正五边形)
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/35a85edf8db1cb1384dbc980cf54564e93584bf7?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
福利手游APP(下载搜0.1)
手游充值0.1折
¥免费分享
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/3bf33a87e950352aee22359c4143fbf2b3118be6?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
手游代理加盟限时特惠!
推广手游拿分成
¥79元
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0b7b02087bf40ad1a7a2bf74452c11dfa8eccee7?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
手游加盟代理自助注册页面
入行手游项目必看教程
¥198
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/2f738bd4b31c8701827b5973357f9e2f0608ff52?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
新自由之刃(百人同屏)
满攻速魂环版传奇
¥1.76复古
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/2e2eb9389b504fc240905b90f7dde71191ef6d5c?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
绝世仙王之八荒寻仙录
超高人气仙侠手游
¥无折扣返利
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/8601a18b87d6277f18be79ae3a381f30e824fcfc?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_450%2Ch_600%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
自由之刃2(新)
冰龙魂环复古经典
¥新版复古传奇
查
看
更
多