(1) | (2) | (3) | (4) | (5) |
C | A | B | A | C |
图一:16÷2=8 8÷2=4
3.14x8 ÷2-3.14x4
= 3.14x64÷2-3.14x16
=100.48-50.24
=50.24
|
图二:3.14×2²÷4-2×2÷2
=3.14×4÷4-2×2÷2
=3.14-2
=1.14
|
图三:12÷2=6
3.14×6 ÷2+12×6÷2
= 3.14×36÷2+12×6÷2
=56.52+36
=92.52
|
周长:3.14x10÷2+10+5×2
=15.7+10+10
=35.7
|
面积:10÷2=5
3.14x5 ÷2+10×5
=3.14x25÷2+10×5
=39.25+50
=89.25
|