The gold medal of the 2008 Olympic Games is round and its diameter is 70 mm. What is the area of the gold medal in square centimeters?
2008年奥运会的金牌是圆形的，它的直径是70毫米，这块金牌的面积是多少平方厘米．
<gadget id="calculator">70 / 10 / 2</gadget>
<output>7/2 = around 3.5</output>

<gadget id="calculator">(7/2) ** 2</gadget>
<output>49/4 = around 12.25</output>

<gadget id="calculator">3.14 * (49/4)</gadget>
<output>38.465</output>

<result>38.465</result>