The side length of a square is 6 cm. Draw a largest circle inside the square. What is the area of the circle in square centimeters?
一个正方形的边长是6厘米，在这个正方形里面画一个最大的圆，圆的面积是多少平方厘米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>