Question

可用两个半圆的面积减去直角三角形的面积

Answer 1

3/2=1.5cm
4/2=2cm
3.14*1.5的平方/2
=7.065/2
=3.5325cm的平方
3.14*2的平方/2
=12.56/2
=6.28cm的平方
3*4/2
=12/2
=6cm
3.5325+6.28-6
=9.8125-6
=3.8125cm的平方