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题:求下图阴影部分周长(单位:cm)。看到这个题目,我的第一个想法就是太简单了,不就是用大半圆的周长减去图中的中半圆和小半圆的周长吗?我不加思索,在作业本上写下一串串算式进行计算。大半圆周长:[(7.5+6)×3.14÷2]+(7.5+6)=11.775+9.42+7.5+6
Title: See Figure Shade Perimeter (Unit: cm). To see this topic, my first thought is too simple, not just use the perimeter of the big half minus the perimeter of the semicircle and the semicircle? I wrote down my homework A string of calculations to calculate. Large semicircular circumference: [(7.5 + 6) × 3.14 ÷ 2] + (7.5 + 6) = 11.775 + 9.42 + 7.5 + 6