3. Square of (a-2b) * 150

=(A-2 * A * 2B squared +46) * 150

= 150A squared -600AB+600B squared.

4。 Pie chart square (A+B/2)- Pie chart square (A/2)- Pie chart square (B/2)

= square of pie chart * A+2ab square +b square -A square -b square /4

=AB/2 faction

AB small pie =3. 14 159265354 omitted.