单选题
In the figure above, a circle is inscribed in a square with side b and a square with side a is inscribed in the circle. What is the area of the square with side b?
(1)a=4
(2)The radius of the circle is
In the figure above, a circle is inscribed in a square with side b and a square with side a is inscribed in the circle. What is the area of the square with side b?
(1)a=4
(2)The radius of the circle is
【正确答案】
D
【答案解析】[解析] 由a=4可求出，内切圆的直径等于[*]，也即大正方形的边长[*]，由此可求出其面积等于32，所以(1)充分；由内切圆的半径等于[*]也可得到大正方形的边长b=4[*]，其面积等于32，所以(2)也是充分的。