The length of a rectangle is 8 cm and the width is 4 cm. Draw the largest circle inside this rectangle. What is the area of the circle in square centimeters?
一个长方形的长是8厘米，宽是4厘米，在这个长方形内画一个最大的圆，圆的面积是多少平方厘米
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>