✔ 最佳答案
1.a=一邊長連接兩條對角線=4ㄍ直角ΔA=1ㄍ葉片=半圓-直角ΔA1=4ㄍ葉片=4*A=2ㄍ圓-4直角Δ=2ㄍ圓-正方形=2*3.14*a^2/4-a^2=(3.14/2-1)a^2=(1.57-1)a^2=0.57a^2=0.57*100=57 cm^2
2.把4ㄍ葉片移動到第1圖位置=> A2=A1=57 cm^2
3.A3=(正方形-A1)/4=a^2-0.57a^2/4=(1-0.57/4)a^2=0.8575a^2=0.8575*400=343 cm^2 4.中央的葉片命名為眼睛Ao=眼睛的餘積=2*(正方形-扇形)Aeye=眼睛=正方形-Ao=正方形-2*正方形+2*扇形=2扇形-正方形=半圓-正方形=3.14*a^2/2-a^2=(1.57-1)a^2=0.57a^2A4=Aeye-A1/2=0.57a^2-0.57a^2/2=0.285a^2=0.285*1600=456 cm^2
2014-11-27 20:40:17 補充:
6-1.
A61=圓形*3/4
=3.14*3*a^2/4
=2.355a^2
=2.355*16
=37.68 cm^2
6-2.
A62=圓形*3/4+小扇形
=圓形*3/4+小圓形/4
=3.14*3a^2/4+3.14*b^2/4
=(3a^2+b^2)*3.14/4
=(3*64+4)*0.785
=153.86 cm^2
2014-11-27 20:52:11 補充:
6-3.
A63=大圓形*3/4+中扇形+小扇形
=大圓形*3/4+中圓形/4+小圓形/4
=3.14*3a^2/4+3.14b^2/4+3.14c^2/4
=(3a^2+b^2+c^2)/4
=(3*144+64+4)/4
=125 cm^2
6-4.
A64=大半圓+中扇形+小扇形
=大半圓+中圓形/4+小圓形/4
=3.14*a^2/2+3.14b^2/4+3.14c^2/4
=(a^2+b^2/2+c^2/2)*3.14/2
=(36+16/2+4/2)*1.57
=46*1.57
=72.22 cm^2
2014-11-27 21:03:53 補充:
6-3.漏打3.14 解答改為485.38 cm^2
2014-11-27 21:08:56 補充:
13.
A13=大圓形*3/4+中圓形/4+小圓形/4
=(3a^2+b^2+c^2)3.14/4
=(3*36+4+1)*3.14/4
=88.705 cm^2
14.
A14=大半圓+中圓形/4+小圓形/4
=(a^2+b^2/2+c^2/2)*3.14/2
=(64+16/2+4/2)*3.14/2
=74*1.57
=116.18 cm^2
2014-11-27 21:20:59 補充:
15.
A15=學校操場
=長方形+圓形
=12*8+3.14*16
=146.24 cm^2
16.
A16=大半圓+中圓形/4+2*小圓形/4
=(a^2+b^2/2+2*c^2/2)*3.14/2
=(100+64/2+2*4/2)*3.14/2
=136*1.57
=213.52 cm^2