扫描二维码，直接登录
题库 / Prep2007E1-PS-72
Athin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle withradius r, and the other is used to form a square. No wire is left over. Which of the following represents the totalarea, in square meters, of the circular and the square regions in terms of r ?
~$πr^{2}$~
~$πr^{2}$~+10
~$πr^{2}+\frac{1}{4}π^{2}r^{2}$~
~$πr^{2}+\left ( 40-2πr \right )^{2}$~
~$πr^{2}+\left ( 10-\frac{1}{2}π r\right )^{2}$~
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。