求图中半圆的面积和周长。
给出你的答案π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="π" style="vertical-align:-3px;height:19px;width:14px" loading="lazy">.
的区域半圆的面积是相同直径的圆的面积的一半,所以从求圆的面积开始。
用直径除以2求半径。
r = 162 = 8 cm{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="R空间等于16空间除以2空间等于8cm空间" style="vertical-align:-17px;height:47px;width:119px" loading="lazy">
把这个代入公式,求圆的面积A = πr2{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="A空间等于r平方" style="vertical-align:-6px;height:23px;width:66px" loading="lazy">.
留下你的答案π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="π" style="vertical-align:-3px;height:19px;width:14px" loading="lazy">.(这意味着不要乘以π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="π" style="vertical-align:-3px;height:19px;width:14px" loading="lazy">).
Afull circle = π82 = 64π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="一个下标满空格圆,结束下标空格等于空格开括号8闭括号平方空格等于空格64" style="vertical-align:-12px;height:29px;width:187px" loading="lazy">
用整个面积除以2求半圆的面积。
Asemicircle = 1264π = 642π = 32π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="下标半圆空格等于空格1半开括号64闭括号空格等于空格64除以2空格等于空格32" style="vertical-align:-17px;height:47px;width:273px" loading="lazy">
面积= 32π厘米2
的周长半圆的长度是由圆的圆弧(周长的一半)和半圆的直径两部分组成的。
用公式求圆的周长C = 2πr{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="C空间等于空间2 πr" style="vertical-align:-6px;height:22px;width:66px" loading="lazy">(或C = πd{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="C空间等于d空间" style="vertical-align:-6px;height:22px;width:61px" loading="lazy">).
将半径= 8 cm代入公式。
再次强调,你的答案是π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="直π" style="vertical-align:-3px;height:19px;width:13px" loading="lazy">.
C = 2π8 = 16π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="C空间等于空格2开括号8闭括号空格等于空格16" style="vertical-align:-6px;height:22px;width:138px" loading="lazy">
用整个面积除以2,求出圆弧的长度(半圆周长的弯曲部分)。
Curved length = 1216π = 162π = 8π{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="弯曲空间长度空间等于空间1半开括号16闭括号空间等于空间16除以2空间等于空间8" style="vertical-align:-17px;height:47px;width:299px" loading="lazy">
把这个加上圆的直径,求出整个周长。
周长= 8π+ 16厘米