一个圆锥,它的底面直径和高均为2R,求这个圆锥的表面积和体积?求答案 已知圆锥的表面积为am2,且它的侧面展开图是一个半圆,求这个...
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体积:V=1/3SH=1/3*1/2*π*r^2*h=1/3*πR3表面积:S=S底+S侧=πR^2+πLR(L是圆锥的侧长,R是圆锥半径)=πR^2+根号5πR^2=根号5 +1πR的平方 L可以用勾股定理计算
表面积:3.14R*R+6.28*R*R=9.42R*R
体积:3.14R*R*2R/3=2.093RRR
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